SB 

3Z5' 



Issued January 13, 1913. 

U. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 263. 

B. T. GALLOWAY, Chief of Bureau. 



METHODS USED IN BREEDING ASPARAGUS 
FOR RUST RESISTANCE. 



J. B. NORTON, 

Physiologist, Cotton and Truck Disease and 
Su(i(ir-J'lan t Investigations. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1913. 



^onogmp^ 



i Issued January 13, 1913. 

U. S. DEPARTMENT OF AGRICULTURE. 

BUREAU OF PLANT INDUSTRY— BULLETIN NO. 263. i| / 

B. T. GALLOWAY, Chief of Bureau. 



METHODS USED IN BREEDING ASPARAGUS 
FOR RUST RESISTANCE. 



J. B. NORTON, 

Physiologist, Cotton and Truck Disease and 
Sugar-Plant Investigations. 




WASHINGTON: 

GOVERNMENT PRINTING OFFICE. 

1913. 



f , 






BUREAU OF PLANT INDUSTRY 



Chief of Bureau, Beverly T. G.u,lowat. 
Assistant Chief of BuTeaUjVfnAAAU A.Taylor. 
Editor, J. E. Rockwell. 
Chief Clerk, James E. Jones. 



Cotton and Truck Disease and Sugar-Plant Investigations. 

SCIENTIFIC staff. 

W. A. Orton, Pathologist in Charge. 

H. A. Edson, J. B. Norton, and F.J. Pritehard, Physiologists. 

C. O. Tpwnsend and L. L. narter, Pathologists. 

W. W. Gilbert and H. B. Shaw, Assistant Pathologists. 

C. F. Clark, G. F. Miles, Venus W. Pool, Clara O. Jamieson, Ethel C. Field, and M. B. McKay, Scientific 

Assistants. 
W. B. Clark, Assistant Chemist. 
H. W. Wollenweber, Expert. 
E. C. Rittue, Assistant. 

A. C. Lewis, L. O. Watson, and Joseph Rosenbaum, Agents. 
263 

D. OF D. 



JA^! 21 1913 



ADDITIONAL COPIES of this publication 
-TjL may be procured from the Superintend- 
ent of Documents, Government Printing 
OflBce, Washington, D. C, at 20 cents per copy 



LETTER OF TRANSMITTAL 



U. S. Department of Agriculture, 

Bureau of Plant Industry, 

Office of the Chief, 

Washington, D. C, July 29, 1912. 
Sir: I have the honor to transmit herewith a manuscript entitled 
"Methods Used in Breeding Asparagus for Rust Resistance," by Mr. 
J. B. Norton, Physiologist in the Office of Cotton and Truck Disease 
and Sugar-Plant Investigations, and to recommend its publication 
as Bulletin No. 263 of the Bureau series. 

This paper deals with the methods developed in the selection, 
pollination, and breeding of asparagus at Concord, Mass. The work 
was done in connection with the rust-resistant asparagus breed- 
ing investigations being conducted at Concord by this Bureau in 
cooperation with the Massachusetts Agricultural Experiment Station. 
The author desires to acknowledge the assistance of Mr. C. W. 
Prescott, of Concord, Mass., who, since the beginning of the work, 
has done everything possible to aid the breeding work, Mr. Frank 
Wheeler, of Concord, Mass., together with many other asparagus 
growers from various sections, has given active assistance in the work. 
Respectfully, 

B. T. Galloway, 

Chief of Bureau. 
Hon. James Wilson, 

Secretary of Agriculture. 
263 '-* Q 



CONTENTS 



Page. 

Introduction "g 

History of asparagus rust 9 

Occurrence of rust in America 9 

Failm-e of spraying methods in the East 9 

Previous attempts at breeding 10 

Massachusetts Asparagus Growers' Association 11 

Preliminary work 12 

Nature of the disease 12 

Effect of the disease 13 

Collection of varieties 14 

Varietal uniformity 16 

Value of uniformity '. 18 

Introduction of uncultivated species I9 

Selection 20 

Preliminary methods 20 

Greenhouse infection 21 

Judging rust resistance 21 

Record of select plants 22 

Protection of select plants from frost 22 

Rust infection to secure select resistant plants 23 

Causes of resistance 23 

>Ecidial stage on resistant plants 23 

Relation of structure to resistance 24 

Relation of vigor to resistance 25 

Breeding 27 

Sex. 27 

Pollination 28 

Methods of hand pollination 29 

Care of seed 31 

Method of testing progeny ' 31 

Use of biometry 32 

Correlation studies 32 

Duplicate tests 34 

Use of correlation studies in breeding work 35 

Vigor of seedlings of male A7-83 43 

Rust resistance 45 

Permanency of rust resistance 50 

Seedlings of 1911 52 

Bud propagation 53 

Pedigree 53 

Number 54 

Name g^ 

Records 54 

263 g 



6 CONTENTS. 

Page. 

Plans for distribution 55 

Suggestions to breeders and growers 55 

Rust resistance 55 

Isolation 56 

Progeny bed 56 

Value of breeding methods 57 

Protection from beetles 58 

Protection of nonimmune fields 58 

Suggestions for rust prevention 59 

Summary 60 

263 



ILLUSTRATIONS. 



PLATES. 

Pago. 

Plate I. Effect of rust on asparagus. Fig. 1. — An asparagus field on Cape Cod, 

Mass., killed out by severe attacks of rust and never replanted. 

. Fig. 2. — Field showing the effect of rust on a nonresistant variety of 

asparagus 10 

II. An old asparagus field at Concord, Mass., killed out by rust 10 

III. Different stages of Puccinia asparagi. Fig. 1. — Teleutospores of 
asparagus rust. Fig. 2. — Cluster-cup stage of rust on an asparagus 

stem 12 

IV. Asparagus branch with sori of Puccinia asparagi in uredo and teleuto 

stages 12 

V. Three plants of the same variety, B114, Argenteuil, showing wide dif- 
ferences in type of mature growth 16 

VI. Types of asparagus shoots 16 

VII. Flowers of Asparagus ofiicinalis. Fig. 1. — Male flowers, the lower with 
some of its perianth lobes removed to show the stamens and rudi- 
mentary ovary. Fig. 2. — Female flowers, the upper with some of 
its perianth lobes removed to show the ovary and rudimentary 

stamens 28 

VIII. Female asparagus plant with branches covered by "glassine" bags 
to keep insects from pollinating the flowers with pollen fi'om 
unknown males, this plant being used to test the comparative 

resistance transmission of several males 28 

IX. Fig. 1. — Asparagus fruit and seed. Fig. 2. — Asparagus stem, show- 
ing the effect of bagging flowers without pollination 28 

X. Asparagus seedlings, showing comparative rust resistance. Fig. 1. — 
Seedlings of 1909 in September, 1909, after a severe attack of rust. 
Fig. 2. —Pedigree seedlings of 1910 in September, 1910, B 136-4 X 
A7-83, showing rust resistance. Fig. 3. — Pedigree seedlings of 1910 
in September, 1910, B136-4, open fertilized, showing lack of resist- 
ance and vigor 28 

XI. Plant "Washington," A7-83, showing the general type of the best 

breeding male used in the rust-resistant breeding work 46 

XII. Plant "Martha," B32-39, showing the general type of the best breed- 
ing female used in the rust-resistant breeding work 46 

XIII. Pedigree seedlings of 1911 after a severe attack of rust. Fig. 1. — 

Wakeman seedling stock, showing tops entirely killed by rust. 
Fig. 2.— "Martha Washington" stock (progeny B32-39 X A7-83), 
commercially immune plants with strong vigor 52 

XIV. Pedigree seedlings of 1911 after a severe attack of rust, showing vari- 

able resistance of Standard Giant Argenteuil, all plants suffering 

from rust 52 

XV. Pedigree seedlings of 1911 after a severe attack of rust, showing plants 
from Standard Reading Giant seed, some nearly immune, others 

rusty 52 

263 7 



8 ILLUSTRATIONS. 

Page. 
Plate XVI. Pedigree seedlings of 1911 after a severe attack of rust, showing 
the effect of crossing A7-83ona female plant (A2-23) of average 

resistance 52 

XVII. Pedigree seedlings of 1911 after a severe attack of rust, showing 
plants from open-fertilized seed of B32-39, usually quite re- 
sistant but lacking in vigor 52 

XVIII. Effect of rust on asparagus seedlings. Fig. 1. — Seedlings at 
the south end of a bed at Concord, Mass., in August, 1910, just 
beginning to rust. Fig. 2. — Seedlings at the north end of the 
bed shown in figure 1 on the same day, showing the destruc- 
tion of plants caused by their proximity to a young bed on 
which cluster cups developed abundantly 52 

TEXT FIGURES. 

Fig. 1. Diagram showing the comparative yields of individual plants of row 

Al, season of 1910 19 

2. Diagram showing the average height of 87 progeny rows of seedlings 

of 1910 in greenhouse 43 

3. Diagram showing the height of 50 seedlings each from A7-25 polli- 

nated with A7-I9 (male) and A7-83 (male), seed weighing between 
0.021 and 0.024 gram 44 

4. Diagram showing the effect on greenhouse seedlings of 1910 of A7-19 

and A7-83 with respect to the average heights and average rust 
resistance of progeny lots in comparison with the progeny from open- 
fertilized seed from the same female plants 50 

263 



B. P. I.— 771. 



METHODS USED IN BREEDING ASPARAGUS 
FOR RUST RESISTANCE. 



INTSODUCTION. 

History of asparagus rust. — Asparagus rust (Puccinia asparagi DC), 
which has caused severe losses to asparagus growers m the United 
States during the past 16 years, is a native of Europe. Common 
asparagus (Asparagus officinalis) grows wild over the greater portion 
of Europe and parts of western Asia and northern Africa. Tliis spe- 
cies, with several closely allied forms, is the normal host plant of the 
asparagus rust. There is nothing in the literature of the subject 
to indicate that the rust is in any way nearly as serious a pest in 
Europe as it has been in America. The comparative immunity of 
the crop m Europe is partly explained on the ground that the rust 
is held in check by its natiu-al enemies and by climatic conditions. 
The gradual development of resistant varieties in Europe has had 
sometlihig to do with this apparent difference in severity of attack. 

Occurrence of rust in America. — The definite occurrence of asparagus 
rust in America was unknown imtil 1896, when its discovery was 
recorded by Prof. B. D. Halsted,^ of the New Jersey Agricultural Ex- 
periment Station. The same year brought reports of its occurrence 
on Long Island- and in Massachusetts and Connecticut. It is very 
probable that the rust had been introduced m some way from Europe 
a year or so previously and had spread without being discovered. 
Since 1896 it has spread over practically the entire area of the United 
States where asparagus is grown. It became a factor in asparagus 
growing in the large fields of California in 1902. 

Failure of spraying methods in the East. — In spite of the general in- 
terest and alarm felt by growers and station workers at the sudden 
appearance and rapid spread of this disease, satisfactory methods of 
rust control have not been developed for the eastern regions. Smith 
says : ^ 

In regard to methods of treatment for the control of the rust it may fairly be said that 
up to the time of the appearance of the disease in California nothing effective and satis- 
factory had been developed in other portions of the country previously affected. 

1 Halsted, B. D. Garden and Forest, vol. 9, 1896, p. 394. 

2 Smith, R. E. BuUetln 172, CaUfomia Experiment Station, 1906, p. 1. 

263 q 



10 BEEEDING ASPARAGUS FOE EUST EESISTANCE. 

Many elaborate experiments with sprays have been carried out by 
different experiment stations, but for various reasons the growers as 
a class have failed to take up the practice of spraying. Here and there 
an isolated case exists where a farmer put in a spraying outfit at con- 
siderable cost and managed to check the rust so as to make his beds 
continue to yield paying crops. Most growers did not take up this 
work on account of its extra cost and trouble, either letting their old 
beds die out (PI. I, fig. 1) or plantmg new fields (PI. II) of such semi- 
resistant varieties as Argenteuil or Palmetto. 

Previous attempts at breeding. — Some preliminary attempts have 
been made to start breeding work to develop resistant strains, but so 
far as the writer knows none of these attempts have been successful. 
Smith ^ makes the following statement: 

A beginning has been made by the writer toward breeding desirable rustproof varie- 
ties by saving seed of such plants from various States, which is being carefully planted 
for such a purpose. Quite a collection is already on hand from promising sources. 
Seed has also been imported from Europe of a number of varieties grown there and 
plants have been obtained from all of these. 

The prehminary work on spraying and variety testing brought out 
the fact that certain European varieties were more resistant to rust 
than the ordinary strains grown in the United States at the time the 
rust was introduced. 

Hexamer ^ in his book on asparagus says : 

All the cultivated varieties of asparagus are readily affected by the rust, although it 
has been found that some varieties, notably Palmetto, are less susceptible to its attacks 
than others. 

Smith,^ under a discussion of varieties, makes the following state- 
ment: 

There is no question that some varieties of asparagus are more resistant to rust than 
others. This difference appears much more in new beds, planted after the rust out- 
break started, than in those which existed at the time. So much is this true that in 
the East the rust problem seems well-nigh solved by the growing of Palmetto aspara- 
gus, yet in the first years of rust the difference in favor of this variety was slight 
and often not at all apparent. In 1900 Sirrine wrote that " The fields of Long Island 
have been watched every year since 1896, with the result that only slight, if any, 
differences in favor of the Palmetto were to be noticed, except that in some cases it did 
not succumb as early; " yet at present in the same fields the Palmetto alone remains 
and is being extensively planted. Mr. William Conover planted a field on his place 
in New Jersey with three rows of Palmetto, then three rows of Conover's Colossal, 
alternately, and after a few years the Palmetto was still green when the other variety 
was practically exterminated so that those rows had to be replanted with Palmetto. 
There is no doubt whatever that this variety is much less affected and less injured 
by rust in the long run, even though it does not always appear at first. The Argen- 

1 Smith, R. E. Asparagus and Asparagus Rust in California. Bulletin 165, California Agricultural 
Experiment Station, 1905, p. 95. 

2 Hexamer, F. M. Asparagus, Its Culture for Home Use and for Market, 1901, p. 140. 

3 Smith, R. E. Op. cit., p. 94. 

263 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate I. 



w^^^^^^ ^■^'" *^^^^ 




tl 


^^^^E^'.'-" 


...^imm^ 


' "'"■ -■^■^f.v. 





Fig. I.-An Asparagus Field on Cape Cod, Mass., Killed out by Severe Attacks 
OF Rust and Never Replanted. 




Fig. 2.— Field Showing the Effect of Rust on a Nonresistant Variety of 
Asparagus. Row B24 (in the Center) would have been as Vigorous as 
THE Rows on Either Side, but for Rust. 

(From a photograph taken September, 1908, after the second season's growth.) 
EFFECT OF RUST ON ASPARAGUS. 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate II. 




^m 



I H 

CO 
IXl 



qU. 



INTKODUCTION. 11 

teuil (Bonvallet's Giant, French, and other trade names) is, if not identical with 
Palmetto, indistinguishable from it, and equally rust proof. Among all the American 
varieties no great difference exists, and they are in fact probably all selections from 
the old Conover's Colossal. * * * In a rusty field of any variety plants can be 
seen here and there which are greener, less affected, and more nearly rust proof than 
the average of the field. 

- Massacliusetts Asparagus Growers' Association. — The publication 
in 1905 of Bulletin 165 of the California Agricultural Experiment Sta- 
tion by Prof. Ralph E. Smith, demonstratuig the value of spraying and 
preventive measures in fighting rust, reawakened the interest of 
eastern growers. The general interest in plant breeding at this time, 
particularly in its application to the breeding of disease-resistant 
varieties of crops, suggested the possibility of its application to aspar- 
agus in fighting the rust. The fact that individual plants of a variety 
as well as different varieties as a whole varied in then* rust resistance 
showed that the breeding proposition was not impossible. These 
facts led in 1906 to the organization of the Massachusetts Asparagus 
Growers' Association, with the object of securing by plant breeding a 
rust-resistant variety of asparagus. This association enlisted the 
cooperation of the Massachusetts Experiment Station and the United 
States Department of Agriculture. A cooperative plan of work was 
drawn up, under which, with some modification, the work has been 
carried out. The Department made collections of seed and plants 
from various sources and furnished the services of its experts in carry- 
ing out the breeding work. The Massachusetts station furnished the 
funds to run the work at Concord, Mass., where a branch experiment 
station was established on the farm of Mr. Charles W. Prescott. 
Beginning with the fall of 1908, the department has borne all of the 
expenses in connection with the breeding work, the funds formerly 
supplied by the Massachusetts station being needed for the proper 
development of the fertilizer and nutrition work on asparagus at the 
Concord station. 

It must be understood at the outset that this work was intended to 
develop a rust-resistant strain of asparagus and not to discover 
remedial measures to help the nonimmune varieties already growing. 
Spraying treatments, etc., have been recommended by plant pathol- 
ogists for years, but none have been generally adopted by the growers. 
The Massachusetts Asparagus Growers' Association started out with 
one idea, namely, the production of a strain that would be so immune 
to rust that the farmer would need to pay no attention to fighting 
the disease. This object has been kept constantly in view, and at 
present the prospect of success is so certain that no experiments with 
sprays will be undertaken. Nine out of ten growers in the East will 
not spray, anyway. Breeding work will produce better yielding types 
of commercially rust-immune asparagus, which will drive out the 
older fields as fast as it is possible to produce the stock. 

268 



12 BEEEDING ASPAKAGUS FOR RUST RESISTANCE. 

PRELIMINARY WORK. 
NATURE OF THE DISEASE. 

In taking up breeding work for disease resistance, a knowledge of ^ 
the life history of the organism causing the trouble is usually con- 
sidered necessary. Previous work done in America on the life his- 
tory of the asparagus-rust fungus by Halsted, Stone, Smith, and 
others has given us a basis of sufficient breadth to go ahead without 
further work. As a matter of fact, the methods of breeding used in 
this work have not depended on a knowledge of the life history of 
the rust fungus, except in a minor way. As yet we have found no 
constant differences in structure or physiology between the resistant 
and nonresistant plants. 

Asparagus rust was described in 1805 by De Candolle as Puccinia 
asparagi. It belongs to the order Uredinese, which comprises the 
group of fungi known as "rusts." These fungi are aU parasitic on 
the higher plants, the most familiar examples being the common 
grain rusts. Asparagus rust differs from the grain rusts in being 
autoecious — that is, all stages of the rust occur on the asparagus 
plant, while the grain rusts are heteroecious, the spring stages occur- 
ring on a widely different host, wheat rust, for example, having its 
spring stage on barberry. The disease known to growers as aspara- 
gus rust is always the du*ect result of an infection from spores of 
Puccinia asparagi and, contrary to opinions held by manj'- growers, 
is not caused by fertilizers, soil or weather conditions, insects, or any- 
thing else of this nature. However, once the disease is introduced, 
these other factors may influence its development and intensity. 

The first activity shown in the spring by the rust occurs about the 
same time that the shoots of asparagus begin to appear above ground. 
At this time the resting spores of the fungus begin to germinate. 
From each ceU of these spores there arises a short segmented filament, 
bearing four smaU sporidia. These sporidia are carried by ah or 
water into contact with the young shoots just coming through the 
ground and on germinating send their mycelium through the epi- 
dermis of the shoot and establish themselves in the asparagus shoot. 
This mycelium after a growing period of less than a month, varying 
with weather conditions, starts to produce spores. These spores are 
located under the epidermis in groups commonly known as cluster 
cups or gecidia (PI. Ill, fig. 2). These secidia finally rupture the epi- 
dermis of the asparagus shoot and the light-orange spores are liber- 
ated. Accompanying the cluster-cup stage on asparagus are found 
honey-yellow spots of smaller size, known as spermogonia. These 
spermogonia produce small sporelike bodies that resemble the male 
spores of related orders, but which are now apparently functionless. 

263 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate III. 




Fig. 1 .— Teleutospores of Asparagus Rust. Near the Center of the Cut on 
THE Right is a Uredospore. X180. 




FiQ. 2.— Cluster-Cup Stage of Rust on an Asparagus Stem, x 3. 
DIFFERENT STAGES OF PUCCINIA ASPARAGI. 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate IV, 




Asparagus Branch with Sori of Puccinia asparagi in Uredo and Teleuto 

Stages. X5. 



PEELIMINAEY WORK. 13 

The spores from the chister cups are usually roCiiided, orange yellow, 
and 1-celled. They are carried by an- currents and lodge on the 
stems or cladodes of the asparagus plants. These spores germinate 
in the presence of moisture and produce a mycelium which gi-ows 
mto the asparagus plant through the stomata or breathing pores. 
These spring spores provide the infection which causes the summer 
rust or uredo stage. It is in this stage that the serious damage is 
done. The first signs of summer rust appear in about two or three 
weeks after the development of the cluster cups. The -uredo spores 
appear in clustei"s of single-celled, red-brown spores which rupture 
the epidermis and are carried away by the ah currents to reinfect 
other plants. At this stage the rust spreads rapidly. In warm 
weather accompanied by dew at night, the life cycle from uredo spore 
to uredo spore is often less than 12 days. This is shown by observa- 
tions on seedling asparagus plants in the summer of 1909, when rust 
was repeatedly found on shoots that had been out of the ground less 
than 12 days. Beginning its attacks in the region of Concord about 
the latter part of June or first part of July, the uredo stage continues 
into October. Accompanying it and sometimes occurring alone is 
the teleuto stage (PL III, fig. 1), the fall stage, which goes through 
the winter to provide the spring infection. From the common name, 
fall rust, it might be assumed that this stage would be found only in 
the fall, but it has appeared regularly with the uredo stage at Con- 
cord durmg the summers since 1908 (PI. IV). This is due to the 
fact that it appears under unfavorable circumstances, such as dry 
weather or prolonged periods of cool weather. 

Asparagus rust has an active parasite m the fungus Darluca flum , 
a parasite of rusts in general, which is usually present in the rusted 
fields and is found attackmg the rust in all its stages. During foggy 
or rainy periods m summer when the rust suffers most from Darluca, 
its attacks are reenforced by several saprophytic fungi, which often 
give a mildewed or molded appearance to shoots that have been 
mjured by rust. 

EFFECT OF THE DISEASE. 

While the effect of asparagus rust is not seen directly in the mar- 
keted product, nevertheless it is quite injurious. The damage is due 
to the weakening of the plants by the attacks of the rust on the shoots 
during the summer after the cutting season is over. It is during the 
gromng season that the plants store up food for the next spring, and 
if the shoots are injured or broken off the next season's food supply is 
accordingly diminished. When the rust attacks a plant no injury is 
apparent until the formation of the spore clusters ruptures the epi- 
dermis and allows excessive evaporation from the stems. The shoots 

263 



14 



BREEDING ASPARAGUS FOR RUST RESISTANCE. 



then wither and die. Attacks on the smaller branches and cladodes 
show a deadening effect shortly after the rust sori appear. On the 
whole the mechanical injury seems to be greater than any other. The 
attacks on young shoots in the late summer when the rust has become 
abundant are apt to be quite severe. This is due to the almost com- 
plete mfection that takes place omng to the large number of uredo- 
spores blowing about while the growth is quite tender just as it comes 
through the soil. Spores are often developed from these infections 
before the shoot has had time to branch out and produce cladodes. 
These spore clusters or sori often are so numerous that they crack off 
the epidermis from large areas and the plants rapidly wither or stop 
growing. 

COLLECTION OF VARIETIES. 

The first work in starting breeding experiments was the accumu- 
lation of a collection of varieties from different sources. It was the 
aim to include in this variety test all possible sources of rust-resistant 
plants. In order to get the work started as soon as possible, eight 
rows of yearling roots were planted on the trial grounds at Concord, 
Mass., during May, 1906. These roots were contributed in lots of 
100 by local members of the Asparagus Growers' Association, as shown 
in Table I. Row 9 was added the next season from roots obtained 
by Mr. Prescott. 

Table I. — Roots planted for breeding experiments in field A. 



Row. 


Variety. 


Source. 


1 


Set May 5. 1906: 


Anson Wheeler, Concord, Mass. 


2 


Do 


Do. 


3 




F. E. Foss, Concord, Mass. 


4 


Do 


Do. 


6 


Palmetto (Long Island grown) 


Anson Wheeler, Concord, Mass. 


7 




Do. 


8 




Wilfrid Wheeler, Concord, Mass. 


9 


Set April 17, 1907: 


W. H. Rseve, Mattituck, Long Island. 









During the fall and winter of 1906 a larger collection of seed and 
roots was obtained from most of the seedsmen in America and Europe 
and from interested growers in the asparagus region of the East. 
Mr. C. W. Prescott made a trip in the fall of 1906 through the aspara- 
gus regions of Long Island and New Jersey, securing seed from resist- 
ant stocks and fields. These lots of seed from all sources were ger- 
minated in flats in the greenhouses at Washington, D. C, in March, 
1907; shipped to the field at Concord, Mass., in May, 1907; and 
planted in their permanent place in the trial rows. This treatment 



263 



PRELIMINARY WORK. 



15 



was very severe and many plants failed to grow. Judging by the 
resistance and vigor of the plants in 1907, larger orders were placed 
that fall for seed of Late Argenteuil from Vilmorin-Andrieux & Co., 
of Paris, and for Reading Giant from Sutton & Sons, Reading, Eng- 
land. These lots of seed were grown in 1908 at Concord and were 
planted in 1909, 2^ acres of Argenteuil and practically the sam.e of 
Reading Giant. No new strains have since been planted. 

Table II shows the varieties planted in 1907 from the seed and 
roots obtained the previous fall and winter. It was the intention to 
have about 100 seedlings or about 10 roots from each lot. 

Table II. — Asparagus varieties planted in field B at the Concord Asparagus Experiment 

Station. 



Row. 



90 
92 
94 
96 
98 
100 
102 
104 
114 



Name of variety. 



FKOM SEEDLINGS GROWN AT WASHINGTON. 



Dreer's Eclipse 

Palmetto (Prescott 10) 

Hub 

Moore's Giant 

...do 

Palmet to 

Mammoth Prolific 

Donald's Elmira 

Colossal 

Rust Resistant 

Colossal 

Perfection 

Seedling 

Late Argenteuil 

Vick's Mammoth 

Sutton's Perfection 

Reading Giant 

Early Argenteuil 

Barr's Canadian 

Mammoth Emperor 

Barr's Mammoth 

Columbian Mammoth White. . . 

....do 

White German 

Erfurt Giant White 

Snow Cap Giant 

Giant White Head 

Barr's New White 

Sutton's Giant French 

Snow Head 

Glory of Biimswick 

Palmetto 

Batavian 

Purple Dutch 

J'rench Giant 

Erfurt Giant 

Bonvallet's Giant 

Early Argenteuil (Prescott 14). 

Giant Argenteuil 

Palmetto 

Palmetto (Prescott 12) 

Palmetto (Prescott 2) 

Palmetto ( Prescott 3 ) 

Palmetto ( Prescott 4) 

Palmetto ( Prescott 5 ) 

P.onvallet (Prescott 13) , 

Bay State , 

Palmetto ( Prescott 1 ) 

Palmetto ( Prescott 6) 

Palmetto (Prescott 7) 

Palmetto (Prescott S) 

Palmetto (Prescott 9) , 

Pal metto ( Prescott 11) , 

Nutmeg state 



Source. 



Henry A. Dreer, Philadelphia, Pa. 
Walter Van Fleet, Little SUver, N. J. 
Joseph Breck & Sons, Boston, Mass. 
Schlegel & Fottler, Boston, Mass. 
W. W. Rawson & Co., Boston, Mass. 
J. M. Mitchell, Mount Pleasant, S. C. 
Moore & Simon, Philadelplila, Pa. 
Jolmson & Stokes, Philadelphia, Pa. 
J. M. Thorbum & Co., New York, N. Y. 
B. R. Tillman, Trenton, S. C. 
Jas. Barr & Sons, London, England. 
H. W. Buckbee, Rockport, 111. 
R. P. Wakeman, Southport, Conn. 
Mlmorin-Andrieux & Co., Paris, France. 
James Vick & Sons, Rochester, N. Y. 
Sutton & Sons, Reading, England. 

Do. 
Vilmorin-Andrieux & Co., Paris, France. 
Barr & Sons, Loudon, England. 
James Carter & Co., London, England. 
Jas. Barr & Sons, London, England. 
D. M. Ferrv & Co., Detroit, Mich. 
J. M. Thorljum & Co., New York, N. Y. 
Vilmorin-Andrieux & Co., Paris, France. 
Ernest Senary, Erfurt, Germany. 

Do. 
Hememann, Erfurt, Germany. 
Jas. Barr & Sons, London, England. 
Sutton & Sons, Reading, England. 
Platz & Son, Erfurt, Germany. 
Ernest Penary, Erfurt, Germany. 
N. L. Willet Drug Co., Augusta, Ga. 
James Carter & Co., London, England. 
Vilmorin-A.ndrieux & Co., Paris, France. 
Jolmson <fe Stokes, Philadelphia, Pa. 
Heincmann, Erfurt, Germany. 
Vaughan's Seed Store, Chicago, 111. 
Peter Henderson & Co., New York, N. Y. 
Vilmorin-Andrieux & Co., Paris, France. 
George Tait & Sons, Norfolk, Va. 
Jas. J. H. Gregory & Sons, Boston, Mass. 
W. H. Reeve, Mattituck, Long Island, N. Y. 
Joseph Cooper, Mattituck, Long Island, N. Y. 
A. L. Downs, Mattituck, Long Island, N. Y. 
J. G. Do^vns, Mattituck, Long Island, N. Y. 
Vauqimn's Seed Store, Chicago, 111. 
A. D. Shamel, U. S. Dept. of Agriculture. 
Joseph Cooper, Mattituck, Long Island, N. Y 
Long Island Seed Co., Mattituck, N. Y. 
Edwin Beeckman, MiddletoA\'n, N. J. 
W. B. Conover, Red Bank, N. J. 
Dr. S. L. De Fabry, Little Silver. N. J. 
Hiram Worthley, Concord, Mass. 
A. D. Shamel, U. S. Dept. of Agriculture. 



57206°— Bui. 263—13- 



1 



16 



BREEDING ASPAEAGUS FOR RUST RESISTANCE. 



Table II. — Asparagus varieties plantedin field B at the Concord Asparagus Experiment 

Station — Continued. 



Row. 


Name of variety. 


Source. 


1 


ROOTS OBT.VINED FROM GROWERS AND SEEDSMEN. 

Dreer's Eclipse 


Henry A. Dreer, Philadelphia, Pa. 

Joseph Breck & Sons, Boston, Mass. 

Moore & Simon, Philadelphia, Pa. 

Johnson & Stokes, Philadelphia, Pa. 

Dr. B. T. Galloway, U. S. Dept. of Agriculture. 

J. M. Thorburn & Co , New York N Y 


4 


Hub 


12 


Mammotli Prolific 


14 


Donald's Elmira 


15 
16 


do 

Colossal 


20 


do 


Jas. Ban & Sons, London, England. 
H. W. Buckbee, Rockport, El. 


22 


Perfection 


26 


Late Argenteuil 


28 


Vick's Mammoth 




30 


Sutton's Perfection 


Sutton & Sons, Reading, England. 
Do. 


32 


Reading Giant 


34 


Early Argenteuil 




36 


Barr's Canadian 


Jas. Barr & Sons, London, England. 
Jas. Carter & Co., London, England. 


38 


Mammoth Emperor 


40 


Barr's Mammoth 


41 


do 


Johnson & Stokes, Philadelphia, Pa. 
D. M. Ferry & Co., Detroit, Midi. 


42 


Columbian Mammoth White 


44 


do 


J. M. Thorburn & Co., New York, N. Y. 


48 


Erfurt Giant White 


Ernest Benary, Erfurt, Germany. 
Heinemaim, Erfurt, Germany. 


49 


Erfurt Giant 


50 


Snow Cap Giant 


Ernest Benary, Erfurt, Germany. 
Heinemann, Erfurt, Germany. 


52 


Giant White Head 


54 


Barr's New White 


Jas. Barr & Sons, London, England. 


56 


Sutton Giant French 


Sutton & Sons, Reading, England. 


58 


Snow Head 


Platz & Son, Erfurt, Germany. 


60 


Glory of Brunswick 


Ernest Benarj'^, Erfurt, Germany. 


62 


Palmetto 


N. L. Willet Drug Co., Augusta, Ga. 


64 


Batavian ■ 


James Carter & Co., London, England. 
Vilmorin-Andrieux & Co., Paris, France. 


66 


Purple Dutch 


68 


French Giant 


Jolmson & Stokes, Philadelphia, Pa. 
Vaughan's Seed Store, Chicago, 111. 


72 


BonvaUet's Giant 


78 


Palmetto 


George Tait & Sons, Norfolk. Va. 


107 


do 


T. S. Williams, Hattie^ille, S. C. 


108 


Giant Emperor 


John Lewis Childs, Floral Park, N. Y. 


109 


(Unnamed) 


South Carolina. 









In addition to the above-mentioned lots, selections were begun in 
1908 from about 5 acres of Imported Argenteuil and 2 acres of 
selected stock from the imported lot, both on the farm of Mr. Frank 
Wheeler, and from 3 acres of selected stock from Mr. Wheeler planted 
on the station grounds. This last field is being used for fertilizer and 
nutrition trials by the Massachusetts station. 

VARIETAL UNIFORMITY. 

Although many names are included in the collection of varieties, 
few distinguishing characters are to be found to separate the so-called 
varieties, A lot of seedlings would show nearly aU the variations 
found in the whole trial field (PI. V). One lot of Columbian Mam- 
moth White that could have been the purest stock in the field in the 
character of whiteness showed no pure white plants in the whole 
trial row. To judge from the observations made on the varietal lots 
at Concord there are at present no pure strains of asparagus, the 
difference between the various lots being on a percentage basis. 
Thus, one lot may have more large stalks than another, hence it may 

263 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate V. 




o ^ 

LJ < 

UJ 

Ll_ UJ 

u- q: 



55 



-I LJ 

=> °1 

UJ UJ 

I- "- 

Z t 

UJ Q 
O 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate VI. 




Types of Asparagus Shoots. Nos. 1 and 3, Good; No. 2, Too Large at Base; 
No. 4, Rough with Projecting Scales; No. 5, from Short Slow-Growing 
Plant. 



PRELIMINAEY WORK. 17 

be called Giant; another lot may have more white plants and there- 
fore may be given the name '' Wliite" or some similar term. 

The observations at Concord showing lack of uniformity in varieties 
correspond to those of many experimenters and growers elsewhere 
who have written on the subject. 

Ilott/ writing from the standpoint of an English grower, says: 

There are many so-called varieties, yet they differ but little. Messrs. Sutton & 
Sons of Reading have two — Perfection and Giant French — which are somewhat dis- 
tinct. They are both excellent kinds, but whether fchey differ from others going 
by different names I do not know, for culture has a great deal to do with the appearance 
of asparagus, as of human beings. A variety which is sometimes well grown, and 
sometimes the reverse, varies much in appearance, thus favoring the idea of a differ- 
ence of variety. Two other possibly distinct varieties are Argenteuil Early Giant 
and Argenteuil Late Giant, which latter probably keeps longer in the cutting season 
by furnishing shoots later than the first named. Conover's Colossal is another good 
kind, but not superior to those named above. Palmetto reached me a few years ago 
with a startling character. It is said to be both earlier and larger than any other, 
but planted side by side with all the kinds above mentioned I have not yet found 
it [to] display its alleged virtues. It came from America, and it is possible that it 
went over there first from Europe, probably from England, for I find it about as good 
as many others. As to size, it is smaller than Sutton's Giant French. The only 
other variety which I am going to mention is one which was sent out by Messrs. Bun- 
yard. They named it Harwood's Early, and it is noteworthy as being alleged to be 
the earliest to become fit for the markets. It certainly has in my experience for 
three years in succession started before the other kinds. There is, however, as I 
consider, far more importance in soils, sites, and general cultivation than in differ- 
ence of variety, and whereas the cultivation differs materially, the varieties do 
not, in any great measure, differ from one another. 

H. W. Ridgway,^ of Swedesboro, N. J., one of the best growers in 
the East, in a recent discussion of asparagus growing, says : 

Variety is the principal thing, but in making our selection of variety let us not 
put too much dependence on the name. It may be misleading, owing to the fact 
that many growers are not acquainted with the varieties and accept the name given 
them without questioning its authenticity. There is only one species and several 
varieties; one-half of the names that wo hear are not varieties. The grass so named 
has been caused by methods of cultivation, highly-manured land, and climatic condi- 
tions, and differ from each other only by a single characteristic which will rapidly 
disappear when grown under climatic and soil conditions different from that in which 
they originated. 

Smith in his work in California found no uniform varieties and 
many names applied to strains that differed from each other in no 
appreciable way. The same opinion as to varietal differences is 
held by most growers who have been interviewed. 

One thing is apparent in looking over tests of varieties, namely, 
that no real pedigree breeding has been done. A search through 

1 Ilott, Charles. The Book of Asparagus, 1901, p. 2. 

2 Ridgway, H. W. Extract from Thirty-sixth Annual Report, New Jersey State Board of Agriculture, 
1909, pp. 11 J-115. 

263 



18 BEEEDING ASPARAGUS FOR RUST RESISTANCE. 

available literature reveals no pedigree work nor even plans for any. 
The variability of the best imported strains seems to settle the 
matter (PI. VI), at least as far as Europe is concerned. The results 
from one generation of pedigree breeding at Concord show that 
uniformity can be obtained in many characters by proper selection 
of parent types, yet it is highly probable that little real advance in 
asparagus varieties has been made since the time of the Koman 
gardener who grew stalks of such size that three weighed over a 
pound. 

A quotation from Hexamer ^ shows the best method recommended 
by authors in giving advice as to seed growing. This method is 
practically the same as that recommended by most European writers 
and is that followed by some of the best growers in this country. 

In order to insui'e the production of the very best asparagus seed a sufficient number 
of pistillate or seed-bearing plants, which produce the strongest and best spears, 
should be selected and marked so that they may be distinguished the following spring 
when the shoots appear. These clumps should be close together and near some 
staminate or male plants which have to be marked likewise, as without their presence 
fertile seed can not be produced. The number of the male to the female plants should 
be about one to four or five. The following spring all the sprouts of the selected male 
plants are allowed to gi'ow without cutting. On each hill of the female plants the 
two strongest and earliest stalks are allowed to grow, cutting the later appearing spears 
with the others for market or home use. Thus these early stalks of both niale and 
female plants bloom together before any other stalks, and the blooms on the female 
plants will be fertilized with the pollen of the selected male plants. This last is of 
prime importance, for on proper fertilization depends the purity of the seed as weU 
as the vigor of the resultant plant. Not all seed of even a good plant properly fertilized 
should be used for reproduction, as of the seeds gathered from any plant some will 
be better than others. Only the largest, plumpest, and best-matured seeds should be 
used, for by saving these the most nearly typical plants of the sort will be most certainly 
produced. The selection of the best seed from typical plants is as essential to success 
as are good soil, thorough cultivation, and heavy manuring. 

VALUE OF UNIFORMITY. 

The uniform distribution of good asparagus over the field is a 
matter that has received some attention from growers. The yield 
and type of the individual plants in most varieties differ widely, and 
it is probable that less than half of the plants pay a profit. This differ- 
ence in ^deld is illustrated graphically in figure 1. A separate record 
was kept of the cut of each hill in row Al, New American, Geneva- 
grown stock, in its fifth season in permanent place in the bed. The 
diameter of each stalk was measured, tliis method being considered 
more reliable than to take the weight. This diagram shows that 37 of 
the hills cut above the average and that unquestionably many plants 
in the row were not paying for ground rent, fertilizer, and labor. 

> Hexamer, F. M. Asparagus: Its Culture for Home Use and for Market, 1901, p. 27. 
263 



PKELIMINAEY WOEK. 



19 



This row represents an " aver- 
age" lot of plants. Some 
beds in Concord and vicinity 
show a higher average effi- 
ciency, but many are lower. 

INTRODUCTION OF UNCULTI- 
VATED SPECIES. 

In connection with the in- 
troduction of asparagus vari- 
eties for the rust -resistant 
work, several wild species 
have been brought in by the 
Office of Foreign Seed and 
Plant Introduction from dif- 
ferent regions for distribu- 
tion. Asparagus (Aspara- 
gopsis) virgatus from South 
Africa was tested at Concord 
in 1908 and proved to be en- 
thely free from rust. The 
following winter aU the plants 
were killed by cold. Later 
trials at Washington have 
shown that this species is 
quite tender. Mr. George 
W. Oliver, of this Bureau, 
has tried to cross this species 
with A. officinalis, but with- 
out success. A. officinalis 
pseudoscaher was tested in 
1911 at Concord but proved 
quite susceptible to rust. So 
far the attempted crosses be- 
tween this variety and the 
parent form have failed to 
give hybrid plants. A. da- 
vuricus, a related form from 
China, was pollinated in 1911 
with A. officinalis pollen and 
has given seedlings that show 
hybrid characters. A. davu- 

263 



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Z ', 


1 S ^ /i 


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1.20 

1.69 

S.67 

2.33 

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-97 

I.S^ 

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2.'6 

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3i& 

I.S6 

4.42 

8.T2 

1 .73 
1 .66 

S.SO 

.72 

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.34 

2.3S 

I.9S 

1 .23 

.38 

.03 

2.70 

1.3/ 

S.39 

.64 

.83 

S.06 

■ 72 

S.6I 

1.46 

.78 

6.14 

4.SS 

.53 

4.63 

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/.80 

3.33 

.86 

.42 

3.8e 

£.27 

i.ao 

.19 
S.02 
3.66 

.30 

.oa 

■4 36 

2 31 

.06 
S£8 

/.ea 
2.eo 

.36 
.83 
.66 
.03 
2.45 

.06 

3.08 
/0.02 
.70 
/.73 
3.13 
2.34 
3.14 
4.33 
.78 
1.73 
1.78 


e 


mm 












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16 
17 
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31 
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33 
34 
3S 
36 
37 
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Fig. 1.— Diagram showing the comparative yields of indi- 
vidual plants of vovf Al, season of 1910. The yield is 
shown in the sum of the squares of the diameters of the 
stalks cut from each hill. 



20 BREEDIlSrG ASPARAGUS FOR RUST RESISTANCE. 

ricus has not been tested for rust resistance. Its size and hardi- 
ness indicate that valuable forms might possibly come from hybrids 
between it and A. officinalis. 

A collection of forms of asparagus from all over the Old World is 
being made, and as these plants come into bloom hybrids will be 
made with Asparagus officinalis wherever possible. Of course, many 
species are not closely related to the cultivated forms and will not 
give fertile hybrids. These forms will be grown to determine their 
possible ornamental value and to aid in a systematic study of the 
group. 

SELECTION. 

PRELIMINARY METHODS. 

The first work of selecting rust-resistant plants was begun in the 
fall of 1908. At that time no definite information was obtainable 
in regard to rust-resistant plants. It was not definitel}^ known that 
the resistance was due to a character inherent in the plant, or to 
some local condition that rendered the plant immune for that en- 
vironment or season only. The relative value of a resistant plant in 
a resistant lot as compared to an equally resistant plant in a lot or 
strain that averaged more rusty was unknown. 

Several hundred marking stakes were made from ordmary lath 
sharpened at one end. These lath can be readily seen at some dis- 
tance in an ordinary asparagus field. The experimental fields were 
gone over and every plant showing exceptional resistance was marked. 
In the fall of 1908 the variety test plats in fields A and B, comprising 
about 2 acres of different strains, were gone over in this way. 
Three acres of Argenteuil, Mr. Frank Wheeler's select stock, on 
the station grounds and several acres on the farm of Mr. Wheeler 
were also included. This work was repeated in 1909 and again in 
1910. In 1909, selections were first made from the new plantings of 
Reading Giant and Late Argenteuil set out in permanent beds that 
spring. These beds have been included in the selection areas since that 
time. Besides some new untested plants, the selections of 1910 
included only those plants of past years that had been progeny 
tested and proved of value as breeders. In 1909 many cross-pollina- 
tions were made between the select plants of 1908. Eleven hundred 
of these seedlings grown in the greenhouse were planted on the 
station grounds in 1910 in four rows with hUls 1 foot apart in 
the row. These pedigree lots were included in the selections of 1910 
and 1911. 

263 



SELECTION. 21 

GREENHOUSE INFECTION. 

When the plans for rust-resistant breeding work were laid out in 
the fall of 1908 it was intended that the experimental infection of 
seedling plants to determine then* relative resistance would be carried 
on during the winter months in the greenhouses at Y\''ashington. In 
this way it would be possible to gain a season. For various reasons 
this plan proved impracticable. The rust is not readily transferable 
in the greenhouses, owing to the lack of dew. The fact that ure- 
dospores do not germinate unless properly ripened on the host is 
another factor. During the fall of 1908 and again in 1909 the rusty 
plants brought into the greenhouses died back, so that the rust 
infection was lost and the new shoots commg up had no rust on them. 
The feeling that the different conditions of moisture, heat, etc., ex- 
isting in the greenhouse might cause an entirely different rust rela- 
tion as compared to that of the field has led to the dropping of this 
part of the plan. The work is now so far along that the greenhouse 
infection work is unnecessary. 

JUDGING RUST RESISTANCE. 

In the work at Concord the preliminary selection of breeding stock 
was begun m the fall of 1908 on fields A and B, planted in 1906 and 
1907. The plants were marked for rust resistance on a scale of to 
10, the zero mark being used for a plant practically nonresistant 
and at the time of selection showing no green whatever as a result 
of a strong rust infection, 10 being the mark for a plant having no 
rust. The intermediate grades were assigned to plants showing in- 
termediate degrees of infection according to the personal judgment of 
the observer. Experience in judging amounts of rust is required. 
The first season's marks are not as accurate as those of later years, 
because the plant as a whole rather than the rustiest stalk was then 
considered. The experience of later years has shown that the rustiest 
stalk in the hill is the best index, as many of the earlier stalks do not 
rust badly. They become hardened and seem more immune than 
the shoots that come up when the rust has become prevalent and is 
giving a strong infection. In making breeding-stock selections in 
the future no plants will be saved that do not show practical immu- 
nity to the rust. 

In connection with the selection work the question was raised by 
visiting experimentalists as to the reliability of the methods used 
in marking resistant plants. In order to test the value of the marks 
assigned, row Al was scored on two successive days, the second 
marking beginning at the other end of the row from the first so as 
to eliminate the factor of memory as far as possible. The result of the 
score is shown in a correlation table (Table III). 

263 



22 



BEEEDING ASPARAGUS FOR RUST RESISTAISTCE. 



Table III. — Coirelation between two independent gradings of row Al for rust resistance, 
September, 1911, to test reliabiliti/ of values assigned by obsei'ver. 

[Coefficient of correlation 0.923±0.013.] 



Grades. 


First marking (grades). 


Fre- 
quency. 


Depart- 
tire 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


from 
mean. 


Second marking: 

1 


4 




















4 
3 
7 
6 
14 
9 
10 
25 
2 
1 


5 


2 


3 




















3 




4 


3 
3 
1 














3 


4 






2 
5 
2 


1 
1 
3 










2 


5 








7 
2 
3 
2 








1 


6 








2 
7 
15 









7 














+ 1 


8 














8 
2 


...... 


+ 2 


9 














+3 

+4 


10 








































Frequency 


4 


3 


4 


7 


9 


5 


14 


24 


10 


1 


81 




Departure from mean . . 


-5 


-4 


-3 


-2 


— 1 





+ 1 


+2 


+3 


+4 







The greatest deviations are in the middle grades, but as these plants 
are not valuable for breeding parents the high correlation between 
the grading in the two., sets of observations from a practical standpoint 
is higher yet. This method of checking up the value of grades as- 
signed in selection work where the personal equation largely enters 
should be followed more extensively than it is at present. The ability 
to accurately judge differences of minor degree adds greatly to the 
value of the work. 

RECORD OF SELECT PLANTS. 

In making selections some permanent record is necessary. Perma- 
nent stakes in the field are not desirable, on account of the spring 
cultivation with a disk harrow. In our experimental plats the plants 
are placed at definite distances apart and a record made of a select 
plant, -giving its row number and plant number to enable it to be 
relocated in the spring. Four-foot lath make cheap and convenient 
stakes which can be seen for some distance in the field. When plants 
in a cutting bed are to be left for seed, it is necessary to mark them 
so the cutters will let them alone. 

PROTECTION OF SELECT PLANTS FROM FROST. 

On account of late frosts occurring after the selected plants are up 
a foot or SO, it is sometimes necessary to cover them over night. 
Manila paper bags are very good for this purpose. When the shoots 
were covered with moist earth at times when the temperature went 
low enough to make ice one-fourth of an inch thick, the stalks froze 
and when the sun came out they thawed out rapidly enough to be killed. 
At the same time the shoots under the manila bags escaped injury. 
A peculiar frost phenomenon v/as observed in June, 1910, when a light 

. 263 



SELECTION. 23 

frost occurred in the lowest portions of one of the breeding fields. 
Glassine paper bags, which are used to cover flowering branches on 
female plants in breeding work, instead of protecting the flowers 
from frost actually increased the injury, so that the flower buds 
dropped off under the bags, while the unprotected buds outside 
remained uninjured. 

EUST INFECTION TO SECURE SELECT RESISTANT PLANTS. 

During the past three seasons there has been an abundance of rust 
during July, August, and September on the experimental grounds at 
Concord. This abundant attack of rust is necessary to obtain selec- 
tions of any practical value. The attack of rust should deaden the 
tops of practically 95 per cent of the young seedlings from standard 
Argenteuil stock in the seed bed, or in its ravages in a commercial 
field of good Argenteuil make it possible for a beginner to pick out 
less than 10 resistant plants per acre as being plainly superior in rust 
resistance to the other five or six thousand. 

So far in this work no asparagus plants have been found that will 
not rust to some extent. There is a -wide difference in susceptibility 
in different varieties. The old American sorts represented in Con- 
cord by Moore's crossbred are practically nonimmune, while Argen- 
teuil and other related European varieties are highly immune, so 
much so that they are not troubled by rust unless a new bed planted 
near by is not being cut in the spring. 

, There is no question that the spread of the rust from one field to 
another depends on the direction and intensity of air currents. On 
the experimental field at Concord the prevailmg \vinds are from the 
northwest. This fact, combined mth the circumstance that the dew 
dries up last on the northwest side of the plant, makes the heaviest 
attacks of rust on the shady side. On account of the direction of the 
prevailing wind at Concord, it is highly advisable to have any infec- 
tion area on the north or west of the seedling bed to be infected. 
Once a field has had a good infection of rust and the resistant plants 
marked, it is not necessary to provide rust in future seasons, as the 
select plants can be tested by growing pedigree seedlings. 

In fact, it is not necessary to test the individual resistance of a 
plant in order to determine its value as a breeding parent. All that 
is necessary is to test a small lot of its seedlings, 

CAUSES OF RESISTANCE. 

Mcidial stage on resistant plants. — An interesting feature of the 
rust-resistant breeding work developed in the spring of 1909, when the 
cluster-cup stage of the rust appeared. The plants that had been 
selected as rust resistant in 1908 were allowed to grow without bemg 

263 



24 BEEEDING ASPARAGUS FOR RUST RESISTANCE. 

,ciit. In addition to these selected plants several nonresistant plants 
were allowed to grow up to be used in crossing tests to determine the 
dominance of the resistant character. No uniform differences in the 
secidial infection could be noticed, many of the most resistant plants 
havmg a better infection than the rusty plants. This development 
caused some doubt as to the nature of resistance and made it seem 
possible that the immunity of the year before might be due to some 
temporary factor. Later in the season when the summer stages of 
the rust appeared this doubt was dissipated, as the resistance again 
appeared in the select plants of the year before in about the same 
degree as in the previous season. 

Relation of structure to resistance. — The fact that sporidia from ger- 
minating teleutospores can infect through the epidermis without 
necessarily entering through the stomatal openings gives an explana- 
tion for the phenomenon just noted and sheds a possible light on the 
«ause of rust resistance m asparagus. 

It is a well-known fact that in the heteroecious rusts the secidial 
stages occur on plants widely different in general character from their 
hosts when in the uredo or teleuto stages. Thus there is reasonable 
ground on which to oppose the theory that rust resistance is due to 
structural differences simply because the gecidial stage appears on 
resistant plants as freely as on nonresistant ones. However, the 
theory that in asparagus resistance has a morphological cause is reen- 
forced by several other points. While little work has been done on 
this problem in asparagus, the evidence tends to show that resistant 
plants have smaller stomata than the nonresistant ones. It may be, 
of course, that the size of guard cells is not closely correlated with 
the actual size of the opening through which the mycelium must pass, 
but it gives a suggestive point of attack in solving the problem. 
When the rust develops in a field in summer, the shoots that came 
up first and have fully matured and hardened develop a lighter 
attack of rust than the shoots which appear during the'heightof the 
rust epidemic. Once the rust gets started in the plant it goes ahead 
in its development equally well in resistant and rusted plants, no 
difference being discernible in the ty])e or vigor of the individual 
sori on plants of different degrees of resistance. 

Ward,^ in liis studies of rust resistance in the genus Bromus, comes 
to the conclusion that resistance is not due to structural causes. 
He says: ^ 

We are hence driven to conclude that the factors which govern predisposition on 
the one hand and immunity on the other are similar to those which govern fertility 
and sterility of stigmas to pollen * * *. 

1 Ward, H. M. On the Relations between Host and Parasite in the Bromes and Their Brown Rust, 
Puccinia Dispersa (Erikss.). Annals of Botany, vol. 16, 1902, pp. 233-315. 

2 Ward, H. M. Op cit., p. 314. 

263 



SELECTION. ' 25 

In a later study of rust resistance Ward * says tha this researches 
'' clearly led to the conclusion that the matter has nothing to do with 
anatomy, but depends entirely upon physiological reactions of the 
protoplasm of the fungus and of the cells of the host." 

Until sufficient evidence has been accumulated on the correlations 
between structure and rust resistance in asparagus the writer does 
not care to claim definitely that the size of the stomata is related to 
the phenomenon of resistance to the attacks of the uredo stage of the 
asparagus rust. The presence of the aecidial stage on the asparagus 
plant gives a point of attack in the search for the cause of immunity 
that is not found in the hetercecious rusts of grasses, and when the 
studies on this point have been completed it is hoped that new light, 
at least, will be thrown on the question of disease resistance. 

Relation of vigor to resistance. — The theory that vigor of growth is 
correlated with resistance, as suggested by some American writers on 
the subject, can not be accepted, for many resistant plants are quite 
small and never produce strong shoots. The trials of the last two 
seasons of two equally resistant strains of Argenteuil stock from local 
growers at Concord show no relation between resistance and vigor. 
About 450 one-year-old seedhngs of each strain were planted in 1908 
side by side on uniform land and under uniform treatment. When 
they were cut for a short time in 1910 each day's yield was separated 
into giant and common grades, using the local grading system. 
One lot gave a total yield over a period of 35 days, from April 23 to 
May 28, of 142-j^ pounds divided into 106y| pounds of giant and 35f 
pounds of common. The second lot gave in the same period only 
65y| pounds total cut divided into 14i pounds giant and 51 3^ pounds 
common. The details of the record are presented in Table IV. 

» Ward, H. M. Recent Researches on the Parasitism of Fungi. Annals of Botany, vol. 19, 1905, p. 21. 
263 



26 



BEEEDING ASPARAGUS FOE RUST RESISTANCE. 



Table IV. — Yield from jive 300-foot roivs of Argenteuil asparagus, showing comparison 
of large and small strains, seasons of 1910 and 1911. 





Large strain. 


Small strain. 




Giant. 


Common. 


Giant. 


Common. 


Date. 


Weight. 


03 


Weight. 


s 


M'Cight. 




Weight. 






o 


i 

o 
O 


a 


o 

a 
a 
O 




o 


1 


a 
o 




1910.1 
April: 

23 


1 
1 
5 
6 

14 
7 
5 

11 
7 
S 
4 
4 
6 
4 
6 
3 
2 
3 


14 
13 
10 

2 

7 


6 
10 

3 

2 
10 

1 
10 
15 
12 
15 

4 


20 
20 
55 
63 

126 
73 
45 
96 
70 
72 
38 
45 
55 
42 
71 
40 
31 
31 




2 

1 

2 
2 
1 
3 
2 
2 
1 
2 
2 
6 
3 
1 
• 2 
1 


8 
9 
8 
4 

S 
2 
4 
2 
5 
6 
5 

10 
4 
2 
1 
6 
5 

15 


15 
19 
57 
34 

65 
45 
29 
73 
74 
66 
35 
66 
60 
54 
90 
48 
51 
55 







1 
1 




1 
1 












8 
13 
10 

14 
9 
12 
10 
5 
14 
15 
10 
13 
7 
8 
7 
8 
5 



7 
11 
9 

23 
20 
9 
9 
16 
25 
12 
8 
10 
6 
7 
6 
6 
4 



1 
2 
2 

6 
2 
1 
4 
3 
4 
2 
2 
3 
2 
4 
2 
1 
2 


11 

3 

1 
1 

5 
8 
11 
4 
12 
7 
15 
13 
13 
14 
2 
3 
9 
1 


20 


25 


29 


27 


61 


2S 


76 


May: 

2 


182 


4 


60 


10 


41 


13 


135 


16 


120 


18 


142 


20 


91 


21 


108 


23 


123 


24 


101 


25 


146 


26 


85 


27 


50 


28 


69 






Total 


106 


13 


1,073 


35 


12 


936 


14 


8 


188 


51 


5 


1,739 






1911.2 

May: 

6 




G 

8 

15 

21 

25 

16 

12 

8 

10 

8 

"9 

8 



11 

8 

S 

1 

8 

7 

13 

9 

7 

5 

7 
6 
8 
4 
6 
5 
3 
5 
7 
4 
4 
2 


11 

10 
9 
5 
8 
7 

10 
3 
1 

13 
4 
3 
3 


10 
9 
5 
3 

14 

14 
9 
7 
4 
6 


6 
2 
12 
4 
9 

14 
10 

12 
13 


10 

71 

82 

127 

189 

211 

142 

99 

72 

89 

67 

83 

74 

58 

103 

77 

74 

13 

79 

72 

121 

89 

60 

48 

(■>0 
53 
80 
48 
62 
51 
30 
59 
67 
40 
47 
30 



3 
3 
3 

4 
3 
2 
1 
2 
2 
2 
2 
2 
1 
3 
5 
2 

1 
1 
5 
5 
4 
3 

3 
2 
3 
2 
1 
1 
1 
2 
4 
3 
1 
1 


5 

7 

8 

12 

8 

6 

13 

8 



7 

7 

10 

13 

7 

8 

1 

8 

10 

10 

13 

1 

10 
13 
3 

5 

8 

6 

11 

13 

14 

3 

9 

4 

5 

1 

11 


10 
82 
85 
86 
105 
84 
61 
41 
45 
61 
59 
62 
80 
33 
88 
117 
69 
20 
42 
44 
113 
140 
125 
70 

S3 
67 
98 
67 
56 
55 
37 
67 
111 
88 
20 
48 




1 
1 

2 
4 
4 
2 
2 
2 
2 
2 
1 
1 
1 
2 
2 
2 


3 
2 
3 
2 
1 
1 

1 

1 


1 

2 
1 
1 
1 
1 
1 
1 


2 
8 
4 
8 

11 
4 

12 
8 

11 
1 
7 
9 

10 
6 
9 

11 

1 
6 

13 
4 

10 
5 

11 

11 
11 
10 
11 
6 

9 
7 
15 
13 
2 
3 


2 
22 
15 
28 
51 
50 
30 
34 
33 
25 
30 
18 
18 
17 
27 
28 
23 

1 
39 
34 
38 
33 
16 
19 

21 
9 
20 
9 
18 
23 
20 
20 
23 
20 
16 
15 


1 
4 
5 
8 
8 
7 
5 
2 
2 
4 
5 
4 
5 
2 
7 
9 
5 

4 
4 
8 
5 
4 
3 

6 
3 
3 

1 
3 
3 
2 
3 
5 
2 
4 
2 



7 

10 
10 
10 

11 

2 
11 

8 
1 

12 

11 
. 14 

10 
5 
4 
9 


3 

13 
8 

14 

3 
12 
3 
15 
6 
14 
12 
10 
9 
1 
2 
6 


32 


8 


153 


9 


133 


10 


208 


11 


233 


12 


214 


13 


147 


14 


65 


15 


80 


16 


129 


17 


132 


18 . 


132 


19 


146 


20 


78 


21 


192 


22 


246 


23 


161 


24 


23 


26 


112 


27 


108 


28 


224 


29 


184 


30 


128 


31 


101 


June: 

1 


176 


2 


114 


3 


108 


4 


49 


5 


104 


7 


113 


8 . 


103 


9 


105 


10 


164 


11 . . 


50 


12 


137 


14 


70 






Total 


305 


10 


2,737 


100 


6 


2,519 


70 


12 


845 


164 


10 


4,654 







» Total yield in 1910: Large strain— 2,009 stalks, weighing 142 pounds 9 ounces (average weight per stalk, 
1.14 ounces); small strain— 1,927 stalks, weighing 65 pounds 13 ounces (average weight per stalk, 0.54 ounce). 

2 Total yield in 1911: Large strain— 5,256 stalks, weighing 406 pounds (average weight per stalk, 1.23 
ounces); small strain— 5,449 stalks, weighing 235| pounds (average weight per stalk, 0.69 ounce). 

2C3 



BKEEDING. 27 

The results in 1911, showing the yield for a full season, were more 
conclusive. Again lot 1 was far superior in size and total yield, 
giving 406 pounds total, of which 305f pounds w^ere of giant grade 
and lOOf pounds common. Lot 2, while actually producing more 
stalks in the season, had only 235f pounds total, 70f pounds giant 
and 164f pounds common. The record for 1911 is also shown in 
Table IV. If there was any difference, the advantage in rust resist- 
ance is in favor of lot 2; moreover, about 10 of the best plants were 
reserved out of lot 1 as breeding parents and the cut is thus perceptibly 
reduced. In the region around Concord it has been noticed frequently 
that the poorer parts of the field had less rust when other conditions 
were equal, so that the apphcation of chemical fertilizers has been 
held by some farmers to be the cause of the rust. 

BREEDING. 

The real work of breeding started m the spring of 1909. Many 
questions of importance in regard to methods had to be settled, for 
to a certain extent we were on unknown ground. Asparagus was 
generally recognized as a dioecious plant, but several writers and 
observers had suggested that parthenogenetic seeds were sometimes 
produced. The relative dommance of rust resistance in heredity was 
uncertain m asparagus. Biff en ^ in his work with disease resistance 
in the small grains had shown an apparent dommance of suscepti- 
bility, but in asparagus there is no question at present that the 
heterozygous forms are intermediate in resistance. The possibility 
of obtammg a combination between strains that would give first- 
generation hybrid vigor was unportant, and above all was the hope 
of findmg two parent plants that would give a highly uniform progeny 
in rust resistance and vigor. 

In starting the work a study had to be made of the natural and 
artificial methods of polUnation. Means had to be devised to control 
the pollination work so that rehable pedigrees could be established. 
The paragraphs that follow comprise an account of the observa- 
tions made and the resulting methods developed and now in practice 
on the different phases of these problems. 

SEX. 

Asparagus officinalis is fimctionally dioecious, but the flowers on 
both types of plants contain rudiments of the organs of the opposite 
sex. Under field conditions asparagus apparently requires the aid 
of insects to secure proper pollination. As a rule, no seed is set with- 
out the aid of bees and other insects carrymg pollen from the flowers 

1 Biffen, R. H. Journal of Agricultural Science, vol. 1, 1905, p. 40; vol. 2, 1907, pp. 109-128. 
26.3 



28 BREEDING ASPARAGUS FOR RUST RESISTANCE. 

of male plants to the stigmas of the flowers on the female plants. 
Hermaplirodite plants occur now and then, but so far in our experi- 
ments can not be considered a factor in seed production. In the 
flowers of the typical female plant the rudiments of stamens (PL VII, 
fig. 2) exists, but the writer has never seen one developed sufficiently 
to even suggest the possibiHty of self-pollination. On the other hand, 
the male plants often show a well-developed ovary with style and 
stigma and sometimes even a typical stigmatic surface. The great 
majority of male flowers, however, lack a well-developed ovary, the 
rudiment being about half the size of the normal ovary of the female 
flower and lacking any stigmatic development (PL VII, fig. 1), the 
style often being completely abortive. The hermaphrodite plants 
mentioned above are always of the male type, the flowers being for 
the greater part pure male in that they lack the complete and func- 
tional ovary. In one wild male plant examined the flowers at the 
extremities of the branches were typically female with well-developed 
stigma and abortive anthers. This male had been used for pollination 
work in testing rust resistance of select plants. Another hermaphro- 
dite plant which produced seed that would germinate and make 
healthy, vigorous plants had many flowers whose ovaries lacked the 
stigmas. The berries on these hermaphrodite plants are very small 
and rarely have more than one seed in them. The seeds are usually 
peculiar in that the seed coats are not entirely developed. The 
seeds appear mottled black and white, varying from the white of the 
uncovered endosperm in the smaller seeds to well-covered, entirely 
black seeds in which the coats have had their normal development 
and have completely covered the endosperm (PL IX, fig. 1). These 
small seeds make weak plants and in many cases abnormal ones, but 
the larger, better developed seeds make healthy seedlings of normal 
type. As yet these seedlings have not been observed in bloom, so 
the sex inheritance is unknown. 

POLLINATION. 

During the blooming period of 1909 and again in 1910 branches of 
pistillate plants were covered with paraflin paper bags to exclude 
poflen-carrying insects (PL VIII). Although more than a hundred 
of these check trials were made, in no case did any seed set from 
flowers that opened under the bags. The ovaries would swell and 
apparently start to develop good berries, but after reaching about 
one-third of the ordinary diameter they would turn yellow and drop 
off. The uncovered flowers on the same stem set seed abundantly 
(PL IX, fig. 2 ) . That tliis failure to set seed is due to a lack of polHna- 
tion is shown by the large number of seeds secured under bags when 

263 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate VII. 




Fig. 1.— Male Flowers, the Lower with Some of Its Perianth Lobes Removed 
TO Show the Stamens and Rudimentary Ovary. The Perianth Lobes are 
Longer than in the Female Flower, x 5. 




Fig. 2.— Female Flowers, the Upper with Some of Its Perianth Lobes Removed 
TO Show the Ovary and Rudimentary Stamens. The Perianth Lobes are 
Shorter than in the Male Flowers, x 5. 



FLOWERS OF ASPARAGUS OFFICINALIS. 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate VIM. 




Female Asparagus Plant with Branches Covered by"Glassine" Bags to Keep 
Insects from Pollinating the Flowers with Pollen from Unknown Males, 
This Plant Being Used to Test the Comparative Resistance Transmission 
OF Several Males. 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate IX, 




C3 I- 
O CO 



^^^< 



LL O < (-) 
LI. L_ UJ '-^ 

UJ CO 

UJ ^ O I 



o 



z z o - 

CO ^ I o 

H I- o 

2 o c5 ta . 

liJ Q. Z « 

I- "- - u 

ro L_ CC CO UJ 

55 oQ 17^ 



cc > a (E H 

< ^ UJ CQ UJ 

Q- CO > I- 

^2 CE o _ < 

'. § CO ^ ll 

<M H < O O 

tD 
U. 




< I- CO 
I z ^ ^ 

I < o ^ 
• -I < o 

a._iz 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate X. 






BREEDING. 29 

the flowers were hand-pollinated. The insect visitors to the asparagus 
flowers are largely bees of difi'erent kinds. The honey bee is most 
plentiful during the blooming season, and at this time of the year 
practically all of the pollen that comes into hives that are near aspara- 
gus fields is the rich, orange pollen from the staminate asparagus 
flowers. Apparently a large amount of nectar is also produced. 
This is shown particularly in flowers under bags where the bees have 
been kept away until the flower is old, when it is so abundant as to 
interfere with pollination. In addition to the honey bee many small 
wild bees frequent the asparagus flowers. Some of these small bees 
are a nuisance in the pollination work, apparently being especially 
attracted by the extra quantity of honey in the protected flowers. 

The wind seems to play little part in pollmation, as the male 
flowers retain their load of pollen until they begin to wither unless it 
is removed by a bee. The pollen hangs together in masses and does 
not become powdery until the flower dries up. 

The anthers of the staminate flowers deliisce throughout the day, 
but by far the greater portion open in the morning hours. On a 
bright, sunny day they are nearly all open by the time the dew is 
gone. Cold, damp weather seems to prevent the anthers from open- 
ing, so that after a long spell of rainy weather a large number of 
flowers will be spoiled, as the anthers do not open well except when 
fresh. There is quite a range of variability in this respect and also 
as to the time the anthers open in the morning. Some days when the 
atmosphere was moist some staminate plants could not be used in 
pollination work until an hour or so after most of the others, and on 
misty or damp, cloudy days these plants would refuse to shed their 
pollen at all, while plants near them would yield abundant supphes. 

METHODS OF HAND POLLINATION. 

In the work of hand pollination in asparagus very little apparatus 
is required. The principal requirement is to prevent the random 
poUination of the pistillate flowers by insect visitors. So far in this 
work we have largely depended on paraflSn paper bags. A good 
quaUty of paper known as *'glassine" is used. This paper is nearly 
transparent and is tougher and wears better than any other paraffin 
paper obtainable at a reasonable price. During the spring of 1910 
many of these bags went through a three-days' storm of wind and ram 
without injury. The bags are attached and held on by short pieces 
of No. 18 office wire to which is attached a small eyelet string tag 
for records. The office wire is purchased in small rolls and cut up 
with a pair of shears into pieces about 4 inches long. The bags are 

263 



30 BKEEDIXG ASPAKAGUS FOR EUST EESISTANCE. 

placed over the branches of the female plant, gathered at the mouth, 
and firmly held by bending a piece of wire around the bag about an 
inch or two above the mouth. Ordinarily two branches are included 
in the bag in order to brace each other and prevent the wind from 
whipping the bags around or brealdng the stems. Tliis wire is a great 
time saver over twine, as it does away with tying and untying at a 
time when minutes are valuable. This wire is also used in tying 
the main stalks to stakes to keep them standing against storms. 
Plain copper wire of equal weight is apt to cut and wear into the 
stems or through the bags. 

In the season of 1911, cages constructed of ordinary fly-screen wire 
cloth were used to cover the select plants both male and female. It 
was discovered later in the season that a very small wild bee was 
squeezing in through the meshes and pollinating flowers. In the 
future a finer mesh copper-wire screen will be used. The season 
of 1911 was exceptional for days of extreme heat. Many of the 
branches inclosed under the glassine bags died after they had set 
fruit. Such berries never developed viable seed. Asparagus through- 
out its development is very partial to good ventilation and any pro- 
tective measures for pedigree work must take tliis into account. 

The female plants to be tested can be bagged about the time the 
first flowers are ready to open. At this time the branches are tough 
enough to bend readily without breaking. Flowers that have opened 
are picked off before the branch is bagged. 

The work of pollination is best done in the morning hours just 
after the dew is gone. The desired male plants are visited and a 
collection made of flowers undisturbed by bees or other insect visitors. 
These flowers are placed in small shell vials lined with absorbent 
paper and with a stopper of absorbent cotton. The vial keeps them 
from drying out and losing their pollen and from becoming mixed 
with flowers from other plants. All vials used should be properly 
labeled to prevent mistakes. 

In selecting male flowers only those are taken whose anthers have 
dehisced their pollen. The poUen in a freshly opened flower clings 
in an orange mass around the stamens at the throat of the bell-shaped 
flower. Flowers that have been visited by bees have lost most of 
this mass and the lighter color of the anther waUs gives a much lighter 
color to the anther cluster. These flowers should be rejected, as they 
are liable to be mixed with foreign pollen. 

In pollinating, the bag is removed from the female branch. A 
flower from the bottle of male flowers is taken out and grasped lightly 
in the right hand, using the thumb and finger or a pair of forceps. 
With the left hand a flower on the female branch is carefuUybent 

263 



BREEDING. 31 

into such a position that it can be touched with the pollen mass in 
the male flower. If the flowers are brought lightly together so as not 
to injure the stigma, the stigmatic surface will be well covered with 
poUen and in the course of a few days the ovary will swell into a full- 
sized berry. With a Httle practice pollination becomes a matter of 
routine work. The whole male flower is used in pollination, and this 
method has proved very satisfactory, doing away with the use of 
brushes or other pollinating devices which are apt to cause mixing of 
poUen from different males. After all the female flowers that are 
open are pollmated the bag is replaced and the tag marked with iden- 
tifying data. One male flower will usuaUy pollinate ten or more 
female flowers, leaving enough poUen on each stigma to be plainly 
visible to the naked eye. 

CARE OF SEED. 

After the various pollinations are made on select plants in spring 
and early summer considerable time must elapse before the seed is 
ripe and ready for harvest. Cultivation is apt to break off branches 
unless great care is used. Asparagus beetles must be guarded against. 
The various accidents considerably reduce the percentage of seed set. 
The berries should not be harvested until they are ripe and soft, other- 
wise the seed is apt to be shriveled and of poor quality. The seed 
when in lots of less than a hundred berries is harvested by picking the 
berries from the plants in the field and placmg them in small manila 
bags, which are labeled on the outside with sufficient data to distin- 
guish the different lots and stored temporarfly in racks in a well- 
ventilated room. After the berries have begun to wither they can be 
stored in ventilated storage boxes without injury until such time as 
it is convenient to clean them. The lots of berries are crushed and 
washed in water, the pulp and skins washed out, and the clean seed 
allowed to dry thoroughly. The seed is then placed in shell vials, 
labeled and corked, and stored for next year's planting. The seed of 
Asparagus officinalis retains its viabflity for several years if properly 
handled. 

METHOD OF TESTING PROGENY. 

The first work in testing transmission of relative rust resistance was 
in the summer of 1909. The previous fall samples of seed had been 
saved from various plants of different degrees of resistance. Twelve 
lots of these seeds were planted in duplicate in short rows in seed flats 
on July 13. When the shoots appeared, July 26, and for several suc- 
ceeding days, fresh uredospore material was dusted over the flats. 
The following table shows the relative rust resistance of the rows of 
these seedlings from observations made September 3, 1909. 
57206°— Bui. 263—13 3 



32 



BKEEDING ASPARAGUS FOR EUST EESISTANCE. 



Table V. — Duplicate test of seedlings of 1909 from plants of varying rust resistance to 
show relative transmission of susceptibility. 





Source of seed. 


Type of plant. 


RaJik of seedlings in resistance. 


Row. 


First lot. 


Second 
lot. 


Average. 


1 


Al-6 


Badly rusted, near rusty bed. . . 
Very resistant female 


7 
6 
3 

10 
4 
2 
5 

11 
9 

12 
8 
1 


9 

5 

7 

8 

3 

4 

2 

10 

11 

12 

6 

1 


8 


2 


A3-61 


5 5 


3 


A4-7 




5 


4 


A4-17 




g 


5. 


A7-5 




3 5 


6 


A7-15 


do 


3 


7 


A7-25 


. ...do. . .. 


3 5 


8 


B24-27 




10.5 


9 


B24-28 


do . 


10 


10 


Old field 


Rusty 


12 


11 


do 




7 


12 


Frank Wheeler; old bed 


Best resistant female 


1 









An inspection of the table shows that the asparagus plants transmit 
resistance to their offspring in about the same relative degree that 
they resist the rust themselves. Plate X, figure 1, is from a photo- 
graph taken in September, 1909, of lot 1 of this set of duplicates, 
showing plainly the effect of rust on the lots. 

This experiment settled the question of the value of rust resistance 
in the plant as a mark of transmitting power. After this preliminary 
trial, plans were laid to test the lots of seed that were obtained from 
our hand pollinations in 1909. In addition to the hand-pollinated 
lots a sample of open-fertilized seed has usually been saved for com- 
parison in the progeny tests. 

In January, 1910, as many lots of seed as could be conveniently 
handled were planted in seed flats in the greenliouse at Washington. 
Studies of the germination and growth of these lots were made and 
correlations measured between various characters. In the discus- 
sion on the following pages these seedlings are referred to as the 
greenliouse seedlings of 1910 to distinguish them from other lots of 
asparagus plants under observation. 

USE OF BIOMETRY. 

CORRELATION STUDIES. 

The use of statistical methods in breeding is becoming more and 
more popular and in many lines is really necessary. The presenta- 
tion of biometrical studies is now rather common in experiment- 
station bulletins. If breeding is to be put on a progressive scientific 
basis this type of work will of necessity become more prevalent. 
The excessive presentation of correlation studies as such should be 
discouraged among practical workers. The value of any work in 
correlation depends on the possible use that can be made of the facts 
in a practical way. The great number of interrelated biologic phe- 
nomena that occur in any plant need to be understood before one 
character can be used as a basis for selection for a correlated character. 

263 



BEEEDING. 



33 



In the study of a plant like asparagus, where selections must be made 
for rust resistance and yield, two desired characters which do not 
show simultaneously, in order to do efficient work some other cor- 
related character must be substituted for yield. Again, the young 
seedling must be compared with the bearing plant several years 
later so that undesirable stock can be discarded without the neces- 
sity of planting large fields with plants of unknown qualities. Before 
any correlation studies were made all stocks were planted in perma- 
nent beds and grown for years without selection. Since 1910 no 
untested plants have been carried beyond the first season in the 
seed bed, all the poor stock being discarded the first year. In tliis 
way a great saving in field space is accomplished. Of course, care 
must be used in basing selections on one character to get plants 
good in another character. Where the correlation runs above 0.75 
very good results are usually obtained. 

Correlation tables serve a good purpose in checking up the reli- 
ability of tests. The use of duplicate plantings or trials year by 
year to secure data on average performance are valuable only as 
they show a high correlation. 

Correlation tables are used in our breeding wherever possible to 
show the reliability of the observations made. This feature is 
illustrated in Table VI, in which the heights of several lots of the 
greenliouse seedlings on February 7, 1910, are correlated with the 
heights of the same lots four days later, showing that the observa- 
tions taken on either of the two dates were satisfactory. 

Table VI. — Correlation between the heights of the tallest plants in 66 lots of progeny 
rows of greenhouse seedlings of 1910, taken four days apart, February 7 and February 
11, 1910. 

[Heights on February 11, subject; heightson February 7, relative. Coefficient of correlation, 0.941±0.013.] 



Heights on 
February 11. 


Heights on Febraary 7 (i-inch units). 


o 
i 


£9 

« o 


13 


14 


15 


16 


17 


18 


19 


20 


21 


22 


23 


24 


25 


26 


27 


28 


29 


30 


31 


1-inch units: 
18 


1 






































1 



1 





1 

2 
3 
4 
6 
8 
6 
13 
9 
4 
4 
2 
1 
2 

66 


— 12 


19 






































-11 


20 






1 


































— 10 


21 






































— 9 


22 . 








































- 8 


23 








































— 7 


24 








































- 6 


25 














1 




1 




















— 5 


26 
















2 




















— 4 


27 


















2 

1 


2 


















— 3 


28... 




















3 
5 
1 


"i 

1 
3 


1 
1 
3 
4 

1 


1 
1 
1 
4 
4 
2 
1 










— 2 


29 




























- 1 


30 



































31 
























2 
3 

1 

1 








+ 1 


32 


























"i 

1 


1 




+ 2 


33 




























+ 3 


34 






























1 

2 




+ 4 


35 






























+ 5 


36 .. 


































1 
1 

4 
+4 


+ 6 


37 


































4 
+5 


1 
1 

+6 


+ 7 


Frequency. . 

Departure from 
niean 


1 
-12 



-11 


1 
-10 



-9 




-8 




-7 


1 

-6 


1 

-5 


2 
-4 


4 
-3 


2 

-2 


9 

-1 


5 



10 

+ 1 


14 


7 
+3 













263 



34 



BEEEDING ASPARAGUS FOR RUST RESISTANCE. 



DUPLICATE TESTS. 



The use of duplicate plats in testing varieties or in breeding or 
selection is important in checking up results. Unless the correlation 
is high, say around 60 to 70 per cent, the test should be looked on vdth 
doubt. When these data are presented in the form of two overlaid 
curves, the observer is Uable to be misled, as the correlation is hard 
to judge; but this form of presentation is used by many Mrriters, is 
easily constructed, and can be used to show the relation of more than 
two characters at the same time. Still, the fact remains that the 
measure of the correlation is mdefinite. 

Duphcate plantings were made of 33 lots of the greenhouse seed- 
lings, and from them many interesting facts were developed. Table 
VII presents the correlation between the tallest plants in the dupli- 
cate rows from measurements taken February 11, 1910. The corre- 
lation between the average height of all the plants in the rows on the 
same date is shown in Table VIII, and Table IX shows the correlation 
between the tallest plant in the row and the average of all the plants 
in the row. In dealing under ordinary circumstances vdth. progeny 
lots of plants varying in a normal way, these tables shoAv whether 
rapid selections can be based on the best individual in each lot. It 
appears that there is a high probability that an experimenter is per- 
fectly safe in basing selections of future progeny lots on a comparison 
of the means or of either the high or the low extreme. 

Table VII. — Correlation betiveen the tallest plants in two lots of duplicate plants of 
progeny lots of greenhouse seedlings of 1910, February 11, 1910. 



[Lot] 


, subject 


lot 2, 


relative. 


Coefficient of correlation 0.876± 0.028.] 








Height of first lot. 


Height of second lot ( J-inch units). 


o 

1 
a* 
£ 


21 


22 


23 


24 


25 


26 


27 


28 


29 


30 


31 


32 


33 


34 


35 


36 


37 


38 


39 


40 




J-inch units: 
19 


1 






































1 







-14 


20 









1 




























-13 


21 






































-12 


22 








































-11 


23 








































-10 


.24 






































- 9 


25 






































- 8 


26 












1 
























1-7 


27. 


































0-6 


28 





































- 5 


29 


















1 


















2 
1 
3 
4 
5 
3 
5 
3 
3 
1 


1 


- 4 


3D... 
































- 3 


31 
















1 
1 


"i 

3 
1 


1 
2 

"i 




1 












- 2 


32 






























- 1 


33 




















2 

"i 

















34 




















1 
2 












+ 1 


35 


















1 
1 




1 
2 






+ 2 


36 


























+ 3 


37 


























1 


1 


+ 4 


38. 


























1 








+ 5 


39 






































+ 6 


40 . 1 




































+ 7 


41 






1 
























1 








+ 8 








1 
































Frequency 


1 











1 1 


1 


3 


5 


4 





5 


4 


3 


1 


3 





1 


33 




Departure from mean... 


-11 


-10 


-,-. 


—7 


^-5 


-4 


-3 


-' 


-1 





+1 


+2 


+3 


+4 


+5 


+6 


+7 







263 



BKEEDING. 



35 



Table VIII. — Correlation between the average heights of greenhouse seedlings of 1910 in 
two duplicate lots of progeny, February 11, 1910. 



[Second lot, subject; 


arst lot, 


relative. 


Coefficient of correlation 0.826±0.035.] 








Average height of first lot (J-inch units). 


o 

a 
2 


11 


Average height of second lot. 


17 


18 


19 


20 


21 


22 


23 


24 


25 


26 


27 


28 


29 


30 


31 


32 


33 




J-inch units: 


1 


































1 



3 

4 
6 
6 
3 
4 
3 

2 
1 

33 


-8 


21 


































-7 


22 




































-6 


23 




































-5 


24 
















1 




2 
















-4 


25 






















, 








-3 






















3 
2 
1 


"2 














-2 






















2 

2 

"i 

1 








-1 


28 




















1 
1 

"i 





























+ 1 


30 






















1 




2 




+2 


31 






















+3 


32 


























+4 


33 






























1 




1 
1 

2 


+5 


34 . . 






























+6 


Frequency 


1 
-11 



-10 







-8 




-7 



-6 




-5 


1 



-3 


8 
_2 


3 


1 



5 


6 


4| 2 
+3J+4 




Departure from mean 


+ 1+2 





Table IX. — Correlation between height of tallest plant and mean height of progeny 
rows of greenhouse seedlings of 1910, February 11, 1910. 

[Mean height, subject; height of tallest plant, relative. Coefficient of correlation 0.901+0.016.] 





Height of tallest plant in row (inches). 





5| 


Mean height of rov . 


1 


2 




id 


■o 


CO 


^^! 


o 


CO 


s 


t-: 


c= 


■o 


X 


GO 


oi 


00 


s 





^ 


:.! 


1 




03 a 



Inches: 

4.25 


1 




1 




1 

3 

12 
10 
6 
8 
11 
6 
2 
4 
1 

66 


-2.75 


4 50 


-2. 50 


4.75 
















































-2.25 


5.00 
















































-2.00 


5.25 








-1.75 


5. 50 
















































-1.50 


5. 75 














































-1.25 


6. 00 - 














-1.00 


6. 25 


















- .75 


6.50 






















3 


3 


3 
3 
2 


2 
3 
3 


1 
1 

'2 

1 


"2 

1 

'4 


"5 
3 

1 


"i 

4 


'i 

"2 

1 

4 


i 

'i 
"i 
'2 

5 

+ 




+ 


1 

+ 


'i 
1 

+ 


- .50 


6. 75 






















- .25 


7.00 





























7.25 


























+ .25 


7.50. L- 




























+ .50 


7. 75 






























+ .75 


8.00 


































+ 1.00 


8.25 






































+ 1.25 


8.50 




































1 

6 

+ 


+ 1.50 


Frequency 


1 
t 




1 




o 

o 

1 


1 
1 




T 




T 




T 


1 

7 


1 

T 


1 

7 


T 


4 

1 


8 

o 

1 


8 

1 


5 


7 
+ 


9 



+ 




Departure from mean 









USE OP CORRELATION STUDIES IN BREEDING WORK. 

The value of studies in correlation to the practical work of plant 
improvement, while not questioned by those familiar with statistical 
methods, has been doubted by those not in the habit of doing accurate 

263 



36 



BREEDING ASPAEAGUS FOR RUST RESISTANCE. 



work. One or two examples will show the possibilities of the use of 
correlation. 

The relation of the size of the asparagus stalk in the fall to the 
next year's cut is interesthig, as it is necessary in selecting rust- 
resistant plants in the fall to pick those that wUl give large-sized 
shoots. Studies of several plants in row Al presented in Table X 
give a fan- idea of the value of large-sized fall growth m determining 
large-sized spring growth. In the same way the total yield should be 
taken into consideration. This quality is hidden at the time of 
selection and must be correlated with total production of stalks in 
the field in the fall. This relationship was worked out with the 
plants in row Al and the result is shown in Table XI. Certainly when 
the correlation is as high as 0.8 the observer should make an almost 
perfect selection by usmg the correlated character to pick the very 
best plants. 



Correlation hetiveen the diavieters of the largest stalks in 86 hills of row Al in 
the fall of 1909 and in the largest stalks cut in the spring of 1910. 



Table X 

[Diameters of 1909, subject; diameters of 1910, relative. Coefficient of correlation 0.575±0.050.] 



Fall of 1909. 


Spring of 1910 (J-inch units). 


Fre- 
quen- 
cy. 


De- 
parture 


2 


3 


4 


5 


6 


7 


8 


9 


10 


11 


12 


from 
mean. 


J-inch units: 

2 






1 

I 

2 


















1 
20 
32 
23 
7 
3 


2 


3 


1 

1 


1 

4 
1 


7 
6 
3 


3 
12 
5 
2 














1 


4 


5 
7 
3 
1 


1 
4 
1 
2 













5 


1 








-fl 


6 








1 


+2 


7 
















+3 
























Frequency 


2 
-4 


6 
-3 


14 


16 


22 



16 


8 


1 








1 


86 










Departure from mean 


+ 1 


+2 


+3 


+4 -4-^ 


+6 















Table XI. — Correlation between cross section of stems in fall of 1910 and cut in spring 
of 1911 on 82 producing plants of row Al. 



[Fall stem area, subject; spring cut area, 


relative. 


Coefficient of correlation 0.811± 0.025.] 




Fall of 1910 


Spring of 1911 (square inches). 




a 






1 


3 


5 


7 


9 


11 


13 


15 


17 


19 


21 


23 


25 


27 


29 


31 


33 




J-inch square units: 

10 


13 
2 
1 


4 
6 
3 


'"'e 

5 

1 


1 
2 
3 
6 
1 




























18 

18 

10 

14 

4 

4 

3 

2 

1 







1 

1 

82 


_ 2 


30 


"i 

3 
1 
1 


2 
2 

1 
1 
2 

1 
























- 1 


50 


1 
1 

























70 






















+ 1 


90 
























+ 2 


110 






1 






















+ 3 


130 






1 






















+ 4 


150 














2 
















+ 5 


170 


































+ 6 


190 


































+ 7 


210 




































+ 8 


230 




































+ 9 


250 






















1 














+ 10 


270 
































1 
1 

+ 13 


+ 11 


Frequency 


10 
-3 


14 

-2 


13 

-1 


13 



6 


9 

T2 


3 

+3 


2 

+4 





3 

+6 


1 

+7 


1 

+8 



+9 



-t-10 



+ 11 




+ 12 




Departure from mean 





263 



BREEDING. 



Si 



A most interesting interrelation comes in the size of the seedling 
to the weight of the seed. It was early noticed that the greenhouse 
lots of seedlings showed striking differences between progeny lots 
from different female plants. Wlierever enough seed remained 
unplanted to give a fair average, the seed weight was determined and 
a comparison made with the average height of the seedlings in the 
progeny rows. Table XII was obtained with a coefficient of 0.780. 
Wliere future size depends on the start the young seedling gets in 
the bed, the tremendous importance of the use of large seed is at 
once apparent. To further test this correlation, 100 seeds from plant 
C13-5-1, open fertilized, were sown in 1910 under uniform conditions 
of moisture, heat, and light in a soil of uniform texture. Each seed 
was weighed to 0.001 gram, the germination record was made, and 
the height of each seedling was measured daily. No effect of size of 
seed on germination could be determined, but the size of the indi- 
vidual seed showed a very strong influence on the height and rate of 
growth. (Table XIII.) Where the individual seed is taken into 
account the correlation is lower than where the average of several 
is taken, on account of the varying hereditary tendencies in different 
seed of the same weight. 

Table XII. — Correlation between average weight of seed and average height of green- 
house seedlings of 1910 for 42 progeny lots on February 11, 1910. 



[Height, subject; weight, 


relative. 


CoefBcient of correlation 0.780±0.042.] 






Height of seedlings. 


Average weight of seed (milhgrams). 


Fre- 
quen- 
cy. 


De- 
part- 


19 


20 


21 


22 


23 


24 


25 


26 


27 


28 


29 


from 
mean. 


Inches: 

5.75 ; 
























1 
5 
2 
4 
9 
10 
2 
5 
3 
1 


— 1 00 


6.00 


2 

1 
2 
3 


"i' 

1 

1 


1 


1 














— .75 


6.25 














.50 


6.50 ... 




1 
1 
3 
















— .25 


6.75 




1 

4 
1 

2 


1 

2 


2 

1 













7.00 












+ .25 


7.25 










1 




+ .50 


7.50 










1 


2 






-f .75 


7.75 










1 


1 

1 




1 


-fl.OO 


8.00 
















-1-1 25 


























Frequency 


2 

-4 


8 
-3 


3 
-2 


6 

-1 


9 


i 


5 

+2 


1 

+3 


3 

+4 




+5 


1 


42 




Departui'e from mean 


-t-1 













263 



38 



BREEDHSTG AgPAEAGUS FOE RUST RESISTANCE. 



Table XIII. — Correlation between height of shoot and iveight of seed in 100 seedlings 
from weighed seed of C13-5-1, open fertilized, grown under control conditions in green- 
house at Washington in 1910. 

[Height of first shoot April 9, 1910, subject; weight of seed in milligrams, relative. Coefficient of correla- 
tion 0.41±0.056.] 



Height of shoot. 


Weight of seed in milligrams. 


Fre- 
quen- 
cy. 


De- 

part- 


12 


13 


14 


15 


16 


17 


18 


19 


20 


21 


22 


23 


24 


25 


26 


from 
mean. 


Inches: 

3 






1 


























1 

3 
2 
4 
2 
5 
6 
7 

10 
12 
17 
8 
5 
8 
5 
1 

3 
1 


2 50 


3.25 






























—2.25 


3.50 










1 
1 
1 


1 




















2 00 


3.75 




1 
1 




















1 75 


4 




1 




















1 50 


4.25 


















1 25 


4.50 
















3 














1 00 


4.75 












3 
.... 

1 
3 
2 


2 
2 
1 
1 
1 
1 












.75 


5 








2 
2 
1 

1 


1 
2 

"4 
2 
1 


.... 






1 








.50 


5.25 








3 

1 
] 
1 
1 
2 












25 


5.50 


2 












1 

1 







5.75 


-f .25 

4- 50 


6 






3 






6.25 








1 










+ .75 


e.50 










4 


1 

1 
1 








-f 1.00 


6.75 




















+ 1.25 
+ 1 50 


7 




















7.25 






























+ 1.75 


7.50 
























1 






1 


+2.00 


7.75 






















+ 2 25 


































Frequency 


2 


3 


2 


7 


13 


12 


12 


10 


12 


9 


8 


5 


1 


2 


2 


100 








Departure from mean 




-6 


-5 


-4 


-3 


-2 


-1 





+ 1 


+2 


+3 


+ 4 


+5 


+0 


+7 











Table XIV is introduced in order to show that the size of the young 
asparagus seedUng is important in determining the future size of 
the plant. This table shows the correlation existing between the 
average heights of 85 progeny lots while in the seed flats in the green- 
house at an age of three weeks and the average of the same progeny 
lots in their permanent place in the field. The factor of crowding, 
which aids the stronger plants and retards the weaker ones, was 
eliminated by placing the plants in individual pots February 13 
and so maintaining them until they were transplanted to the field 
where they are just beginning to show the effects of crowding in the 
fall of 1911. 

263 



BREEDING. 



39 



Table XIV. — Correlation betiveen average height of greenhouse seedlings in progeny lots 
February 11, 1910 (in l-inch units), and their average height September, 1910 {in inches). 



[Height in September, subject; height in 


February 


, relative. 


Coefficient of correlation 0.552±0.048.] 


Height in September. 


Average height of seedlings February 11, 1910 (|-inch 
units). 


1 
1 


si 




20 


21 


22 


23 


24 


25 


20 


27 


28 


29 


30 


31 


32 


33 


34 




Inches: 








1 
























2 
3 
6 
4 

14 
8 
12 
13 
7 
3 
6 
2 
3 
2 

85 


-6 


10 










2 


















-5 


11 








1 
2 
1 
3 
1 




3 
















-4 


12 








1 
4 
3 
3 
3 














-3 


13 












3 


3 
1 

1 
2 
3 

1 


2 

"2 

1 
1 










-2 


14 


















-1 


15 












2 
1 

1 











16 










+ 1 


17 












+2 


18 














1 

1 




+3 


19 














1 




1 
1 




+4 


20 




















+5 


21 
















1 






2 


"i 

3 

+5 


1 

+6 


+6 


22 
















1 

17 









+7 




-8 





-6 


2 

-5 


8 
-4 


2 


10 
-2 


15 
-1 


C 
+ 1 


8 
+2 


6 

+3 


5 

+4 













In continuing the work with the greenliouse seedlings after they 
were removed to the field in May, 1910, further correlations have been 
studied. Wliile these progeny lots are not exactly a random sample, 
in many respects they answer the purpose of one, the population being 
distributed in monomodal and often nearly normal variation curves. 

In making selections among the young seedlings a general tendency 
among growers is to assume that height is a good index of large-sized 
shoots in future years in the cutting bed. According to the tables 
constructed on the data of height in 1910 and stalk diameter of the 
greenhouse seedlings in 1911 (Table XV), there is a correlation of 
0.634 ±0.013. This result is supported by notes from row Al, where 
the total area of the cross section of the fall stems in 1910 was com- 
pared with the total area of the cross section of the shoots cut in the 
spring of 1911, as shown in Table XI (p. 36). 

263 



40 



BEEEDING ASPARAGUS FOR RUST RESISTANCE. 



Table XV. — Correlation betiveen height in 1910 {inches) and diameter of largest stalk 
in 1911 {^-inch units) of the greenhouse seedlings of 1910. 

[Height in 1910, subject; diameter in 1911, relative. Coefficient of correlation 0.634±0.013.] 





Diameter of stalks in 


1911 


(^inch units). 


a 

3 


» a 


Heigbt in 1910. 


1 


2 


3 


4 


5 





7 


8 


9 


10 


U 


12 


13 


14 




Inches: 

4 




1 

1 
3 

4 


"i 

2 
7 
4 
10 
9 
9 
7 
6 
3 
3 
2 
1 


1 

1 

4 

5 

9 
18 
15 
16 
10 
10 
12 



3 

4' 






















2 
5 
12 
29 
31 
59 
50 
79 
67 
75 
cS5 
79 
73 
56 
CO 
40 
34 
:!0 
19 
23 
11 
7 
3 
2 
2 
2 

1 
1 


IX 


5 


3 
1 






















10 


6 


3 
8 
4 
12 
18 
20 
24 
20 
13 
15 
11 

11 




















g 


7 


2 
9 
11 

5 
14 
18 
28 
30 
28 
29 
25 
19 
14 
4 
8 
5 
5 


2 

1 

1 

3 

11 



6 

14 

17 

11 

9 

12 
12 
11 

5 


1 
1 
3 














s 


8 
















7 


9 
















s 


10 
















5 


11 




3 


5 
2 
3 
9 
10 
10 
16 
11 
10 
8 
14 
6 
7 
2 
3 




1 










4 


12 












3 


13 




1 
1 


"2 


1 
1 










2 


14 












1 


15 















16 






4 
1 
3 
1 

5 
3 

1 
3 
2 

'2 


2 
1 










+ 1 


17 












+ 2 


18 














+ 3 


19 








4 
3 
1 
1 
1 
1 
1 










+ 4 


20 








2 
1 










+ 5 


21 








1 








+ 6 


'22 














+ 7 


23 










2 
3 


3 






+ 8 


24 














+ 9 


25 












2 






+ 10 


26 












1 








+ 11 


27 












2 












+ 12 


28 .. 


















1 





1 
1 






+ 13 


29 
















1 








+ 14 


30 


























+ 15 


31 






















1 








+ 16 


32 






















1 






+17 
































Frequency 


4 


19 


64 


117 


171 


258 


132 


122 


27 


19 


9 


6 





1 


949 








Departure from mean 


—5 


—4 


—3 


—2 


-1 





+ 1 


+ 2 


+3 


+4 


+5 


+ 6 


+ 7 


+8 







Table XVI shows a comparison of height of the greenhouse seed- 
lings in September, 1910, and in 1911. This table serves as another 
illustration of the opportunity of making selections on seedlings. 
Seventy-five per cent of the 1910 lot could have been discarded with- 
out losing any of the 10 best plants of 1911. A comparison of the 
correlation here shown, with the table presented by Clark ^ in his 
studies of timothy in 1910, shows that the conditions at Concord 
were more uniform than those at Ithaca. 

One striking feature in connection with these studies is that the 
reliability of the height correlation is almost equaled by the relia- 
bility of height with next year's size (Table XV). 

Data from mature plants in row Al show a high correlation 
(Table XVII) between the amount of tops on the plants in the fall 
year by year and also a high correlation (Table XVIII) between the 
cut of individual plants compared in successive years. 



» Clark, C. F. Bulletin 279, Cornell Agricultural Experiment Station. 1910. 



263 



BREEDING. 



41 



Table XVI. — Correlation between heights of the greenhouse seedlings of 1910 in 1910 and 

in 1911 (inches). 

[Height in 1910, subject; height in 1911, relative. Coefficient of correlation 0.fi42±0.0126.] 





Height of plants in 1911 (inches). 






Height in 1910. 


3 


6 


9 


12 


15 


18 


21 


24 

1 

1 
1 

5 

1 
2 

"2 
1 


27 
1 

i 

1 
3 

8 
4 
6 
4 
2 
3 
1 
1 


30 

"2 
6 
6 
C 
6 
10 
10 

•i 
1 
2 
1 
1 


33 

'2 

5 
6 
2 
8 
7 
5 
8 
7 
6 
2 
3 
2 
3 
1 
1 
1 


36 

"4 
6 

11 
3 

12 
7 

14 
5 
7 
3 
2 
3 
4 
2 
2 


39 

'3 

1 
4 

11 
9 

11 
5 

12 

14 
8 
3 
2 
5 


42 

'i 
1 

6 
7 
5 

17 
9 

17 

15 
9 
9 
9 

10 
1 
3 
3 
2 
1 


45 

"2 
1 
5 
5 
3 
5 

10 
9 

14 

10 
7 
9 
2 
2 
5 

'2 
1 


48 

"2 
1 
1 
3 
6 
8 
6 

14 
8 

10 

}?. 


51 

'i 

i 
2 
3 
2 
3 


54 

'2 

'3 

4 


57 

'2 

"2 
5 
2 
5 
3 

6 
4 
5 
1 
2 
2 
1 
2 

42 


60 

i 

"2 

"i 

"3 
1 

3 
6 
1 
3 
3 
2 
1 

i 

28 


63 
"2 

12 

+ 


66 

i 
1 
2 

1 

"i 

6 

+ 


69 

1 

7 


72 



c 

CO 

+ 


75 


7 


78 

i 

1 

CO 

+ 


81 

ji. 



+ 


84 

1 
+ 


Inches: 

4 


2 
5 
12 
29 
31 
59 
50 
79 
67 
75 
85 
79 
73 
56 
60 
46 
34 
36 
19 
23 
11 
7 
3 
2 

2 
2 


1 
1 

949 


-11 


5 


1 






2 

1 
2 


i 


"2 
1 

1 


'2 
1 
3 
2 

1 


-10 


6 - - - 


- 9 


7 








- 8 


8 








- 7 


9 












- 6 


10 - ... 












2 

1 


- 5 


11 












- 4 


12 












- 3 


13 
















14 
















911 
4 8 
13 10 


- 1 


15 



















16 
















1 


+ 1 


17 
















8 
8 


9 
6 
5 
5 
5 
4 
2 

i 


+ 2 


18 




















+ 3 


19 




















515 


+ 4 


20 






















4 
3 
2 
4 
2 
2 


7 
5 
5 
4 

1 
1 


+ 5 


21 






















+ 6 


22 






















+ 7 


23 


























+ 8 


24 


























+ 9 


25 






























+10 


26 
































+ 11 


27 . 




























1 

126 




92 

+ 


93 

cc 
+ 


92 

02 
+ 


1 

83 

7 


+ 12 


28 

29 

30 

31 

32 

Frequency 


1 

1 




CD 

T 




7 


5 

o 

1 


1 


7 

(M 
1 


9 

1 


15 

00 

T 


35 

7 


55 

7 


69 

1 


84 

CO 

1 


91 

n 
1 


+ 13 

+ 14 
+ 15 
+ 16 
+17 


Departure from mean . . 


+ 


00 

7 





Table XVII. — Correlation between urea of cross section of fall stems ofroiv Al in 1910 

and in 1911. 

[Stems in 1910, subject; stems in 1911, relative. Coefficient of correlation, O.S59±0.018.] 





Area offcross section of stems in fall of 1911 (J-ineh square units). 


g 


a 



Stems in fall of 1910. 






















CO 





1 










(M 


1 



c5 


i 




CO 


i 




J-tnch square units: 

10 


s 




i 


1 

6 
3 












- 


















18 


- 2 


30 


4 
4 

1 


2 
2 
3 


"2 


1 
1 

4 

2 
1 


















1 


18-1 


60 


2 


4 




















16 
14 
4 
4 
3 
2 
1 



1 
1 





70 




















+ 1 


90 






















+ 2 


110 








1 






















+ 3 


130 


























+ 4 


150 






























+ 5 


170 
































+ 6 


190 


































+ 7 


210 




































+ 8 


230 




































+ 9 


250 


































1 



+ 10 


270 
































1 


+ 11 




































Frequency 


10 
-4 


15 
-3 


10 
-2 


10 
-1 


7 



5 
+ 1 


9 

+2 


7 
+3 


1 
+4 


2 

+5 


2 

+6 


1 

+7 











1 


2 


82 








Departure from mean 


+ 8 


+9 


+10 


+ 111 + 12 







:63 



42 



BREEDING ASPARAGUS FOR RUST RESISTANCE. 



Table XVIII. — Correlation between the yield in 1910 and in 1911 from the plants in row 
Al, given in the sum of the squared diameter* of the shoots from each hill. 



[Cut of 1911, subject; cut of 191C 


, relative 


. Coefficient of correlation, 


0.797± 0.027.] 








Cut of 1910 (square inches). 



a 

3 
C 

(in 


a 




Cut of 1911. 


o 

o 


IN 

2 


o 





10 

2 


CO 


10 









00 












Square inches: 

to 2 


16 
7 
2 
3 






















16 

14 

13 

13 

6 

9 

3 

2 



3 

1 

1 


- 


2 to 4 


6 
6 
2 
1 


1 

3 

5 

"'3' 


















- 4 


4 to 6 


1 

2 
2 
1 


1 














— 2 


6 to 8 




1 













8 to 10 


"4' 
1 
1 


3 
1 

2 










+ 2 


10 to 12 














+ 4 


12 to 14 
















+ 6 


14 to 16 








1 












+ 8 


16 to 18 




















+ 10 


18 to 20 












2 






1 






+ 12 


20 to 22 


















1 


+ 14 


22 to 24 


















1 




+ 16 




























28 
-2 


15 
-1 


12 



7 
+ 1 


7 
+2 


8 
+3 


1 
+ 4 




+5 


2 

+6 




+7 


1 
+ 8 


81 




Departure from mean 









Table XIX shows liow close a selection can be made for stalk 
diameter in 2-year-old plants by saving only the tall plants. This 
method, of course, is much quicker than to measure the diameter of 
the shoots of every plant in the bed. 

Table XIX. — Correlation betiueen height (inches) and diameter of largest stalks 
ix^-inch units) in 1911 of greenhouse seedlings of 1910. 



[Heights, subjec 


; diameter, relative. 


CoeiTicient of coiTelation, 


792+0. OOS.] 






Height in 1911. 


Diameter in 1911 dVinch units). 


Fre- 
quen- 
cy. 


De- 
par- 
ture 
from 
mean. 


1 


2 


3 


4 


5 


G 


7 


8 


9 


10 


11 


12 


13 


14 


Inches: 

3 


1 




























1 





5 

1 

7 

9 

15 

35 

55 

69 

84 

91 

126 

92 

93 

92 

83 

42 

28 

12 

6 

1 





1 



1 


-39 


6 




























-36 


9 .. . 






























-33 


12 


3 


2 
1 
4 
3 
5 
2 
2 


























-30 


15 


























—27 


18. - ... 




3 

4 
6 
19 
13 
10 
5 
4 
























-24 


21 




2 

4 

11 

27 

21 

25 

15 

8 

2 

1 

1 






















—21 


24 
























—18 


27 




3 

8 
29 
29 
29 
38 
19 
11 
4 
1 




















-15 


30 




5 

8 
19 
35 
47 
42 
41 
25 
29 

7 


















-12 


33 .. . 




1 

5 
6 

20 

14 

19 

28 

23 

9 

4 

3 
















— 9 


36 






1 
2 
12 
12 
17 
22 
24 
14 
14 
2 
2 














- 6 


39 


















- 3 


42 






1 
1 
2 
8 
2 
6 
4 
1 
1 
1 















45 








1 

"2 
4 
5 
3 
2 
2 


1 
1 
2 








+ 3 


48 














+ 6 


61 












+ 9 


54 














+ 12 


57 










1 
2 
2 








+ 15 


60 












1 
1 
1 






+ 18 


63 


















+ 21 


66 














+ 24 


69 




















+ 27 


72 




























+30 


75 






























+ 33 


78 
























1 






+36 


81 




























+39 


84 
























1 






+42 
































Frequency 


4 
-5 


19 
-4 


64 
-3 


117 
-2 


171 
-1 


258 



132 

+ 1 


122 

+2 


27 

+3 


19 

+4 


9 

+ 5 


6 
+6" 





1 

+8 


949 




Departure from mean 





263 



BEEEDING. 



43 



All these tables go to show that in asparagus we are dealing with a 
stable plant with a permanent individuality ; that an individual char- 
acteristic observed one year will persist in nearly unmodified form 
in future years. Without a study of this kind any breeding work 
would remain an uncertain proposition for several generations. 

VIGOR OF SEEDLINGS OF MALE A7-83. 

The several lots of hand-pollinated seed with the check lots of open- 
fertilized seed which were sown in the greenhouses at Washington in 



iMne A^/?£//r fiLywrs 



/1 3-6/ Of^V 

• ■ X yl7-S3 

• • It /iT-es 

A3-73 OffK 
.. r /1 7-13 
.. X /l7-ff3 

• • X ^ 7-SS 

• X xo .?3 

. X ^ 7-ia 

^4-€2 OP£7/ 

• • X /n-e3 
.. x/i 7-es 

X 7-Ze Off ^.32 

• • X/I7-/S e.*f 

t . X Bl*-I3 \i.20 

• X /»7-7 
I X A 7^/9 
. ^ BIS-/ 

• X BBt-O 



. X B/e-/ 

I xBss-a 

, X 8S0-/0 

. XB/f^3/ 



■ > X/I 7-e3 

• . X B9S^3 

f • X B99-" 

• • XC7-S-/2 

.. xc/3^3a 

.1 xw-i 

Befr-/r7 a/w 

.. XC-7^/i 

< ' X tv-. 





Fig. 2.— Diagram showing the average height of 87 progeny rows of seedlings of 1910 in greenhouse. The 
measurements were made February 11, 1910, for comparison of open-fertilized and hand-poUiaated 
lots of seed. 

January, 1910, were planted to study the effect of the different par- 
ents on vigor of the young seedlings. These lots of seedlings varied 
markedly in average size, and it was easily seen that the open-fertilized 
lots of seed as a rule were shorter than the hand-pollinated lot 
from the same female plant. The accompanying diagram (fig. 2) 
shows the average heights on February 11 of the entire series of 
seedlmgs arranged m classes showing the different lots of hand- 
pollinated seed with the sample check from the same female. The 
check is shown in black with the different pedigreed lots following 
in outline. A study of the diagram shows that wherever male A7-83 

263 



44 



BEEBDING ASPAEAGUS FOE EUST EESISTANCE. 



was used an added vigor is shown in height over the check, which 
represents an average of the selected males. Of course, this check 
lot is influenced by the proximity of good or bad male plants, but 
usually several males would be about equidistant from any select 
female. Several other males show an added vigor, but the lack of 
rust resistance shown in these lots when exposed to rust in the fall of 
1910 removes them from consideration. This difference of vigor is 
^till maintained in the seedlings of 1910 after growing two years in 
the field. Of course, rust has entered into the effect now, but it cer- 
tainly has not been the whole cause of the marked increase in the 
progeny of male A7-83. 

The size of seed being so important a factor in seedling size, it was 
thought best to continue this study in 1911 on lots of seed of the same 



20 










,^ 


x^^ 






— /^ 7-/3 


/O 

s 

o 






'y\ 


\ 


/ 
/ 


\ 






>__^7-<$V5 




7 


/' 


\ 


/ 
/ 
/ 


"4v 


^/-^ 










/ 




7 

/ 




k 




V 






^- J, 




V-' 


h 




\ 







/3 M /s /e /7 /a /S 20 2/ 



22 23 



Fig. 3.— Diagram showing the height of 50 seedlings each from A7-25 pollinated with A7-19 (male) and 
A7-S3 (male), seed weighiag between 0.021 and 0.024 gram. 

average size. Female plant A7-25 was pollmated with both male 
A7-83 and male A7-19 in the summer of 1910 and carefully weighed 
seeds of the two lots were planted to show the effect both of seed 
size and of vigor from the male. The effect of these two factors on 
the seedlings when 10 days old is shown in Table XX. To show the 
effect of A7-83 on seedlmg vigor, 50 seedlings from each lot repre- 
senting the different males were selected from seed weighing as near 
as possible the same; in each case the weights ranged between 21 and 
24 milligrams. In the diagram shown as figure 3 a comparison is made 
between the heights 10 days after germination of lots of seedlings 
from A7-25 pollmated with these two males. The result shows that 
the added vigor of the lot from A7-83 is due to something besides 
large seed. 

263 



BREEDING. 



45 



Table XX. — Comparison of weight of seed and height of seedlings at 10 days of age from 
two lots of 1910 seed from A7-25 female, the two lots having different male parents, 
A7-19 and A7-83. 



Weight of seed. 




Height of seedlings (centimeters). 


Weight fre- 
quency. 




12 


13 


14 


15 


16 


17 


18 


19 


20 


21 


22 


23 


A7-19 


A7-83 


Milligrams: 

fA7-19 


1 
























1 




13 1 


IA7-83 
fA7-19 

IA7-83 
fA7-19 
IA7-S3 
fA7-19 
IA7-83 
fA7-19 
A7-83 
rA7-19 
IA7-83 
rA7-19 
IA7-83 
rA7-19 
IA7-83 
fA7-19 
IA7-83 
rA7-19 
IA7-83 
rA7-19 
A7-83 
A7-19 
A7-83 
A7-19 
A7-S3 
A7-19 
A7-S3 
A7-19 
A7-S3 
A7-19 
A7-83 
A7-19 
A7-83 
A7-19 
A7-83 




















































1 




14 j 

























































15 -j 












































■■■•, - 








1 




16.: -• -j 
































2 


















3 
































1 
1 

1 


















1 




18 •! 
























1 










4 


1 














7 












...L-^- 








1 






3 


6 


1 














11 




20 \ 





























5 


5 


3 


1 
5 
3 

'4' 
7 
1 
10 
5 
5 

"2" 
3 












14 




21 \ 


















g 










6 


4 

1 
5 
1 
2 
1 


3 

4 
4 
3 

4 
1 
2 
1 










17 




22 ■ 






1 


2 








8 


















13 












1 
1 


4 


2 








18 


24 ■ 






2 








6 








6 
4 
4 
2 
2 


3 


1 






24 














10 








1 






2 


4 
2 
2 


1 






19 












5 

"a 
















2 


2 


1 


11 
































1 


1 
1 
1 






2 


28 

29 
















1 






2 




















2 


4 








































1 


1 




2 


30 












































1 






1 


























A7-19 


1 


2 
2 


6 



20 
2 


26 
5 


14 17 
13 ""> 


7 
17 


2 
15 


1 
6 






96 




A7-S3 


5 


4 


97 











RUST RESISTANCE. 

To any one familiar with rusty asparagus fields the injury caused 
by rust is apparent, yet the actual damage is hard to estimate on 
account of the different seasons affecting the cut of the crop. 

Table XXI shows the relation between the percentage of stem 
cross section of the crop of 1911 to that of 1909 and the rust resist- 
ance of 1910. Several plants growing in 1909 rusted so badly that 
they died before 1911, and are therefore excluded from the table. 
It is reaUzed that the increase in size of asparagus hills is influenced 
by many things other than rust, so that the actual effect of rust is 
much higher than the coefficient given shows. 

263 



46 



BEEEDING ASPAKAGUS FOR EUST RESISTANCE. 



Table XXI. — Correlation between the degree of rust resistance in 1910 and the percentage 
of the stem cross section of 1911 to that of 1909 in row Al. 



Rust resistance, subject 


; percentage of stem cross section 


, relative. 


Coefficient of correlation 0.393+0.065.] 


Rust resistance 
in 1910. 


Percentage of stem cross section of 1911 to that of 1909. 


Fre- 
quency. 


De- 
par- 


20 


60 


100 


140 


180 


220 


260 


300 


340 


380 


420 


460 


500 


540 


ture 
from 
mean. 


Grade: 






6 
2 
2 
1 


2 

2 

"i 

1 

3 

1 


2 
3 
3 
2 
3 

"2 

1 


1 




















11 
9 
8 

10 
6 

10 

10 
6 
8 


J 


1 


1 




1 
















3 


2 


2 
3 
1 
1 

2 

1 
3 


1 
1 

"3 
1 
















2 


3 


1 


1 
1 






1 










1 


4 

















5 




3 
1 






1 








1 


+ 1 


6 


1 


2 












+2 


7 








1 






1 


+ 3 


8 








3 












+ 4 
























Frequency . 


3 
-160 


IS 
-120 


10 
-80 


16 
-40 


14 



6 

+ 40 


8 


1 





2 


1 








2 


78 




Departure from 
mean 


+80 


+120 


+160 


+200 


+240 


+280 


+320 


+360 













In 1910 a study was made of the rust resistance of the seedlings 
started in the greenhouse at Washington and later transferred to 
a permanent place in the field at Concord. The rust attacked the 
field in August, so that in the latter part of September some of the 
nonresistant plants were dead. The seedlings of the several lots 
were then judged as individuals, and Table XXII shows how they 
ranked in rust resistance. Lots 1, 4, 8, 11, etc., are from open-fertil- 
ized seed from the female plants used, while lots 2, 3, 5, 6, etc., are 
from seed hand pollinated from male plants mentioned in the second 
column of the table. A study of the table shows A7-83 to be pos- 
sessed of great power to transmit rust resistance. The results shown 
in this table are those on which our breeding work is now based. 
A7-35 is the only other male showing desirable resistance. This 
male is being tested further and may be selected as a breeding 
plant. But there is now no question as to the desirability of A7- 
83 (PL X, figs. 1, 2, and 3, and PI. XI). 

Table XXII. — Rtist resistance of individual greenhouse seedlings of 1910 in progeny 
lots in the field, September, 1910. 



Parent plants. 


No. 


Indi^ndual rust resistance of seedlings (grades). 


Num- 
ber of 
plants. 


Mean. 


9 


Xc? 





1 


2 


3 


4 


5 





7 


8 


9 


10 


A3-61 




1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
11 
12 
13 








'2 




1 

"i 
2 

"i 




1 

"2 

1 
2 

1 

"3 








1 

"2 
2 
1 

1 
1 
2 
3 

1 

"'3 




2 
2 
4 
3 
3 
1 

"i 

1 
4 
1 
1 
2 


'2 
i 

'i 


3 
5 

'2 

1 

'i 

t 

1 
1 


'i 
'2 


'i 

'i 
'i 


'5 
'i 


9 
14 
15 
10 
10 

9 
10 
10 
10 
15 
11 

9 
10 


6.25 




A7-83 




'"4 
2 
4 




8.50 




B72-85 


5.47 


A3-73 




5.45 




A7-19 


5.50 




A7-83 


7.39 




A7-85 


1 
2 

"i 
'i 


4 
4 
1 
2 
2 

"i 


3 

2 
1 

1 
1 


5.30 


A4-24 




5.00 




A4-23 


6.35 




A7-19 


6.67 


A4-62 




.1. 74 




A7-83 


.V. 


8.19 




A7-85 


6.25 



263 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XI. 




Plant "Washington," A7-83, Showing the General Type of the Best Breed- 
ing Male Used in the Rust-Resistant Breeding Work. 

(Photograph taken June, 1910.) 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XII 




Plant "Martha," B32-39, Showing the General Type of the Best Breeding 
Female Used in the Rust-Resistant Breeding Work. 

(Photograph taken Septeml)er, 1909.) 



BREEDING. 



47 



Table XXII. 



-Rust resistance of individual greenhouse seedlings of 1910 in jjrogeny 
lots in the field, September, 1910 — Continued. 



Parent plants. 


No. 


Individual rust resistance of seedlings (grades). 


Num- 
ber of 
plants. 


Mean. 


9 


Xc? 



2 


1 


2 


3 


4 


5 


6 


7 


8 


9 


10 
1 


A7-25 




14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 
56 
57 
58 
59 
60 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
80 
87 
89 


3 
] 

'i 

i 

'2 
"3 
'i 

;; 

"i 
'i 

13 


1 


'5 

'4 

-. 

i 
i 

"i 

'} 
'i 

"2 
i 

i 
i 
i 

3 

1 

1 
1 
2 

i 
'i 

"i 
33 




2 
5 


2 


1 

'i 

'i 
1 

"i 

'i 

'i 
1 

"3 

3 

1 
"2 

"2 

1 
3 

• - 

"i 

I 

'3 
2 

1 
1 

'i 

'i 

.. 

"i 
2 
2 
2 

i 
1 
2 
4 
2 
2 
2 
2 

'i 
1 

i 

i 
3 

1 
3 
3 

2 
1 
1 
3 


1 

'i 
2 
2 


1 
2 
1 

1 

"6 
3 

"2 

"i 

"i 
5 
2 
2 

2 
3 
2 


2 
3 

i 

'i 
1 
1 

"3 

2 
2 


2 
3 

"3 
3 
4 

1 


1 

'i 

'2 
1 

"4 


2 

4 

"i 

1 

4 
3 

"2 
6 
3 

"i 


'i 

\\ 

"4 
2 

'2 


'2 

i 
1 

"4 

6 

'2 

'2 
'2 
'3 

'2 

2 
"2 

57 


"2 

1 

"i 
2 

"4 
?n 


10 


'6 

■■ 
]] 

12 


10 
15 
10 

8 

7 
18 
10 
10 
10 
19 
15 

8 

9 
10 

9 
10 
10 
11 
10 
10 
10 

9 
10 

9 
10 
10 
10 

9 

9 
10 
10 
14 

8 
15 
10 
10 
14 
10 
10 
11 

8 
10 
10 
10 

9 
10 
11 
10 
10 
10 
10 
10 

9 
10 
10 
10 
11 
10 
10 
10 

9 
10 

9 
10 
10 

9 
20 
14 
19 
10 
15 
19 
10 
10 
10 


5.70 




A7-19 


6.07 




B24-13 


2.70 


A8-9.. . 




5.19 




A7- 7 


5.29 




A7-19 


6.58 




Br2- 1 


5.55 




B24-13 


2.00 


B32-39... 




6.10 




A7-19 


6.82 




A7-19 


6.23 




A7-83 


9.50 




W- 2 


6.39 


B70 14 




5.40 




B98-32 


3 
2 


2 
'i 


"i 
1 
3 

"i 

1 

"'3 

"2 

1 

"2 

"} 

"\ 
2 
3 
2 
4 
2 

2 

1 
1 
3 

""i 

"i 
"3 

HI 


"1 

1 

'2 

1 
1 

'i 

i 
'i 

'i 

'i 

"i 

"i 

1 

'i 

"4 
1 

1 

'i 

36 


5.39 


B84-14... 




4.90 




B12- 1 


5.95 




B88-63 


5.68 




B90-10 


4.20 




B114-31 


3.60 


B84-44 . 




1 
1 

"2 
3 
2 
2 




1 
3 

"i 
1 
2 
2 
5 
2 
2 
5 

"3 

"2 
2 
1 

1 
1 
1 
3 

"2 
3 

"i 

"2 
1 
2 

6 


'i 

"i 

1 

'i 

1 
1 

'2 
'i 

i 


4.85 




A7-19 


'2 

I 

1 
1 

'i 
1 
1 

'i 
1 

"i 

16 


"i 

1 

"2 
2 
1 
3 
1 
2 
3 
1 
2 

"i 
2 

"5 
1 
2 
2 
1 

"2 

1 
1 
2 
4 
1 
7 
1 

3 

1 

"'i 

"2 
2 
2 
3 

"3 
1 

"6 
101 


'i 
1 
5 

'i 
4 

'i 

'2 
2 
2 

"i 
2 
1 
2 

1 

'i 
1 

'2 
4 
3 
1 

"3 

44 


5.78 




A7-19 


7.55 




A7-83 


8.05 




B98-32 


4.15 




B98-44 . . . 


5.25 




C7-5-12 


4.65 




C13-5-33 


5.50 




W- 1 


6.06 


B84-47.. 




47 


"3 

"3 
3 

1 
2 

"3 

1 

"2 
"i 

"2 

1 
2 
4 
5 
1 
4 
2 
1 
1 
2 
2 

"4 
2 
4 
1 
1 
3 
3 
3 

6 

1 
4 
6 
1 
6 

160 




4.10 




C7-5-12 


4.10 




W- 1 


5.39 


BS4-C0... 




3.81 




A7-83 


6.00 




B88-70 


4.05 


B92-43... 




3.70 




A7-19 


5.07 




B98-48 


3.70 




B114-31 


5.45 


B114-51.. 




6.77 




B98-32 


5.44 


B 132-26.. 




6.00 




A7-S3 


8.05 




B88-63 


5.85 


B136-4... 




5.28 




A7-35 


8.25 




W- 1 


5.96 




W- 2... 


3.35 


B 136-24.. 




5.45 




C8-2-45 


4.20 


B 140-25.. 




4.95 




C7-5-12 


5.15 




C13-5-33 


4.33 


B 144-16.. 




4.35 




A7-19 


3.90 




C7-5-32 


2.75 




C13-5-33 


3.77 




C17-1-23 


3.45 




W- 2 


2.00 


C6-3-14.. 




2.75 




A7-19 


4.33 




C7-5-12 


3.55 


C6-3-31.. 




4.94 




A7-83 


7.35 




W- 1 




3 

2 

4 

"i 

"6 

2 
3 




6.05 


C 13-5-1.. 




5.33 




A7-S5 


5.43 




C13-5-33 


3.86 




W- 1 


4.58 


C 19-3-44 . 




3.30 




A7-19 


5.27 




A7-85 


4.21 


C2 1-6-33 . 




3.90 




A7-85 


5.50 




C21-5-47 


46 


130 


27 


3.25 




Total 






951 








. 













57206°— Bul. 263—13- 



48 



BKEEDING ASPARAGUS FOE KUST RESISTANCE. 



Table XXIII shows the height of these greenhouse seedlmgs at the 
end of the season's growth in 1910. Again A7-83 is found standing 
out above the other males in the transmission of vigor. As men- 
tioned on page 44, in respect to the vigor of seedlings of some of the 
males while in the greenhouse, some good lots are found, but they 
are poor in rust resistance, and the male parents have been discarded. 

Table XXIII. — Height of individual greenhouse seedlings of 1910, in progeny lots in 

the field, September, 1910. 



Parent plants. 


6 

'A 

1 

1 
2 
3 
4 
6 
6 
7 
8 
9 
10 
11 
12 
13 
14 
15 
16 
17 
18 
19 
20 
21 
22 
23 
24 
25 
26 
27 
28 
29 
30 
31 
32 
33 
34 
35 
36 
37 
38 
39 
40 
41 
42 
43 
44 
45 
46 
47 
48 
49 
50 
51 
52 
53 
54 
55 
56 
57 


Height in inches. 


OS 

ft 



a 
10 

14 
15 
10 
10 

9 
10 
10 
10 
15 
11 

9 
10 
10 
15 
10 

8 

7 
18 
10 
10 
10 
19 
15 

8 

9 
10 

9 
10 
10 
11 
10 
10 
10 

9 
10 

9 
10 
10 
10 

9 

9 
10 
10 
14 

8 
15 
10 
10 
14 
10 
10 
11 

8 
10 
10 
10 


s 


9 


Xd" 


3 


4 


5 

i 
1 
1 


6 

"i 
i 

2 

'i 
i 

"i 

'i 


7 

'i 
1 

'i 
'i 

'i 
1 

3 

1 

•• 
'i 

i 

1 

'i 
'i 

"i 

'i 


8 
2 

i 

"2 

"2 
2 

'2 

"2 
"\ 
"\ 

"i 

"2 
3 

i 


9 

? 

i 


10 
2 

i 


11 

3 
2 
1 
1 
2 

'i 
1 
1 

'i 

"2 
1 

"2 

"2 

1 
2 
1 

"2 

"\ 
2 
1 

"2 
1 

■■ 
"2 
2 

"i 

"2 
3 

1 
2 
2 

1 

"i 
1 


12 

1 
"i 

"i 

2 
2 

i 

1 

"i 

2 

1 

'2 
'3 

"3 
2 

1 

i 

2 

i 

"I 
'i 

i 

i 

i 
2 

'2 
3 
3 

'i 


13 

"i 

5 

"i 
1 

'i 

"i 
3 

"i 

i 

1 
1 
1 
1 
3 
1 
1 
2 

"i 
1 

1 

i 

"2 

2 
"i 

"2 
i 
'i 
i 
'i 


14 

3 

2 

'i 

i 

2 
3 
3 

1 

'i 
1 

I 

1 
1 

i 
3 
2 

1 
2 
1 

"2 

2 

"i 

"i 

'i 
2 

'i 
3 

'3 

'3 

1 
1 

"2 
2 

\ 


15 

1 
1 
1 
1 

"i 

i 

1 
3 
1 
1 
1 
2 

i 

"2 
2 

1 
1 
1 
1 
2 

"2 

'i 

i 

i 

2 

i 

'i 
1 
2 

"2 

"2 
2 

1 

'i 
4 

1 
2 


16 

"2 
3 

"2 
"2 

"x 

"2 

i 
1 
2 

"2 
3 
2 
1 

"3 

1 

'i 
\ 

"\ 

1 
1 

1 


17 
"2 

'i 

"i 
2 
2 

"z 
3 

1 
1 
1 

"i 

"2 
"i 

'i 
1 
2 
2 

1 

'i 
1 

'i 


18 

': 

"2 
2 

"2 


19 

"2 
2 

"\ 

2 

1 
1 

i 
1 

"2 
i 

2 
1 
1 

1 
2 

"i 

1 

i 

"2 


20 

i 

1 

i 

"2 

"\ 
'i 
"2 

"i 
1 

1 
1 

'i 

1 
1 

.. 


21 
"2 


22 


23 

"i 

i 
1 

1 
2 
1 
2 

i 

1 


24 

'i 


25 

i 
i 

i 

1 

'i 


26 

i 


27 

"i 
i 


28 


29 


30 


31 


32 


§ 
s 


A3-61 




12.20 


A3-73 


A7-83 
A7-85 


16.79 
16.00 
13.20 


A4-73 


A7-19 
A7-83 
A7-85 


12.50 
14.89 
12.10 
12.10 


A4-62 


A4-23 
A7-19 


4' 

.. .. 

'i'3 
3 1 

2.. 
1 1 

7 2 

?.' 

j 

ii 

1 2 

"1" 

i:: 


15.10 
16.00 
15.64 


A7-25 


A7-83 
A7-85 


18.44 
18.10 
14.40 


A8- 9 


A7-i9 
B24-13 


12.07 
9.20 
12.25 


B32-39 


A7- 7 
A7-19 
B12- 1 
B24-13 


10.57 
8.89 

10.00 
8.10 

15.10 


B7(>-14 
B 84-1 4 


A7-19 
A7-19 
A7-83 
W- 2 

B 98^32 


15.21 
12.80 
11.63 
14.22 
12.00 
9.17 
16.70 


B84-44 


B12-1 
B88-63 
B 90-10 
B114-31 


'i 
"i 

i 

'3 

2 
2 
2 

i 
1 


'2 
1 

"i 

'i 

'i 

1 

'3 

"2 
'3 

"2 
1 


14.90 
18.09 
15.00 
14.80 
18.20 


B84-47 


A7-19 

A7-19 

A7-83 

B9S-32 

B98-44 

C7-5-12 

C13-5-33 

W- 1 


19.67 
20.30 
20.44 
14.70 
17.40 
15.60 
15.33 
16.78 
15.70 


B 84-69 


C7-5-12 
W- 1 


14.40 
16.29 
11.63 


B92-43 


A7-83 
B88-70 


12.07 
9.40 
12.60 


B114-51 


A7-19 

B98-48 

B114-31 


11.07 
15.00 
13.50 
12. .36 


B132-26 


B98-32 


11.25 
16.90 




A7-83 
B88-63 


21.30 
17.80 



263 



BREEDING. 



49 



Table XXIII. — Height of individual greenhouse seedlings of 1910, in progeny lots in 
the field, September, 1910 — Continued. 



Parent plants. 


6 

■z 

o 

58 
59 
60 
61 
62 
63 
64 
65 
66 
67 
68 
69 
70 
71 
72 
73 
74 
75 
76 
77 
78 
79 
80 
81 
82 
83 
84 
85 
86 
87 
89 


Height in inches. 


a 
p, 


s 

3 


.1 
% 
a 

1 


? 


X^ 


3 
1 


4 

i 

i 

2 
5 


5 

1 

"i 
1 
1 

9 


6 

'2 
12 


7 

i 

"i 

'2 
1 
3 
1 
1 

29 


8 
'2 

i 

1 
1 
1 
1 

i 

i 

1 

33 


9 
i 

i 

'3 
1 
2 
4 

i 

'3 
1 
1 

58 


10 
1 

'/_ 

"2 
"2 

'3 

"3 
'iO 


11 
'3 

i 

'2 

"i 

2 

'3 
2 

7'i 


12 

'2 

"2 

1 

"i 

66 


13 

"2 
1 

1 
1 

'2 

1 
2 
1 
2 

1 

i 

'2 

1 

i 
1 

'3 

5 
3 
1 

1 

75 


14 

'3 
2 

'2 

"i 

2 
1 
2 

i 

i 
2 
1 

"2 
2 

84 


15 

1 

__ 

__ 


16 

2 
2 
2 
1 
5 

i 

1 
2 

1 

i 

2 
1 

2 

1 
2 

i 
1 
1 
1 

7'' 


17 

1 
1 
1 

"2 

"2 

"4 

"i 

1 
1 
1 
2 

i 
2 

"2 

'SI 


18 
61 


19 

1 

2 

i 

"2 

45 


20 
'3 

i 

"2 

"2 
"i 
'4 

i 

1 
1 
1 


21 
'3 

'2 
1 

i 
"3 


22 
"2 

i 

1 

19 


23 

i 

1 

"2 
2 

"i 

"i 

i 


24 

"2 

1 

'i 

"2 
i 


25 

"2 

7 


26 
3 


27 
.. 

2 


28 

i 

2 


29 
2 


30 


31 

1 


32 

i 
1 


B136- 4 




9 
10 
11 
10 
10 
10 
10 
10 

9 
10 
10 
10 
11 
10 
10 
10 


13.78 


B136-24 


A7-35 
W- 1 
W-2 


19.10 
12.36 
12.10 
14.40 


B14a-25 


C8-2-45 


15.30 
18.90 


B144-16 


C7-5-12 
C13-5-33 


21.80 
14.56 
16.30 


C6-3-14 


A7-19 

C7-5-12 

Cl 3-5-33 

C17-1-23 

W- 2 


14.10 
12.50 
11.18 
10.20 
10.00 
10.20 


C6-3-31 


A7-19 
C7-5-12 


9 9.33 
10 14.70 
9 1,5. ,56 


C13-5- 1 


A7-83 
W- 1 


10 
10 
9 
20 
14 
19 
10 
15 
19 
10 
10 
10 


IS. ,S0 
17.50 
13. 22 


C19-3-44 


A7-85 

C13-5-33 

W- 1 


18.80 
14.43 
20.16 
10.10 


C21-5-33 


A7-19 

A7-85 


12.47 
13.11 
13.90 




A7-85 
C21-5-47 

;al.. 


16.70 
12.00 


To 


''iln 


952 


14 42 





























Among the females, B32-39 (PI. XII) stands out in the 1910 test 
as a good parent for rust resistance. Unfortunately the progeny lot 
of seedlings B32-39XA7-83 was in poor ground and did not show 
well in vigor compared to the open-fertilized lot which was in normal 
soil at the other end of the field. As was found in 1911, this apparent 
lack of vigor was due to poor ground only. 

The accompanying diagram (fig. 4) shows a comparison between 
A7-83 and A7-19, the two males used most in our pollination work 
in 1909, both in rust resistance and vigor transmission on the various 
lots of progeny from different females. Accompanying the records 
for each progeny is that of the check lot open-fertilized from the 
same females. This table shows strikingly the great advantage in 
using pedigreed seed of good parents. Attention is again called to 
the fact that the male plants available for pollmation of the open- 
pollinated seed were, with few exceptions, select plants. 

263 



50 



BREEDING ASPARAGUS FOR RUST RESISTANCE. 



PERMANENCY OF RUST RESISTANCE. 

A study of rust resistance year by year shows the same permanence 
of this character in the plants that was shown in the studies of size, 



P/lff£Afr Pl^A/TS 

5 ^ 

A3-73 

OPEN 
>> XA7-/9 
A '^-73 

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' ' XA7-/0 
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A 8-3 

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' ' XA 7-/9 
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- ' X A 7-/3 
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s 

s 
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/4 

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22 

23 
24 

34 

35 
36 

49 
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67 
66 

73 
74 

83 
34 



y4V£PAGS /y£r/G/^T 0/=- 3££Z>L//VG5 
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PAP£Nr PLANTS 

$ d* 

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OPEA/ 
' ' X A 7-33 
A 3 '73 

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' ' X A 7-93 
A4-62 

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' • XA7'83 
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' • X A 7-83 
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« ' XA7-83 
B&4-69 

OPEN 
» » XA7-83 
B/32-26 

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• ' XA7-83 
C 5-3-3/ 

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' • X A 7-83 




Fig. 4.— Diagram showing the effect on greenhouse seedlings of 1910 of A7-19 and A7-83 with respect to 
the average heights and average rust resistance of progeny lots in comparison with the progeny from 
open-fertilized seed from the same female plants. 

yield, etc. Once the individual plants are learned, their individuality 
is recognized in different seasons. The attack of rust on the green- 
house seedlings in 1910 was very uniform and satisfactory from the 

263 



BREEDING. 



51 



standpoint of selection of rust-resistant plants. In 1911 the rust 
came on very much later and did not get started uniformly over the 
plat. Some lots were attacked as badly as in 1910, but the ends and 
outside rows where exposed to the wmd and plants that were shaded 
by trees failed to show as much rust as in 1910. In spite of this fact, 
the correlation between the rust resistance for the two seasons of the 
individuals included in the tests of both years is quite high (Table 
XXIV). 

Table XXIV. — Correlation between rust resistance in 1910 and in 1911 of greenhouse 

seedlings of 1910. 

[Resistance in 1910, subject; resistance in 1911, relative. Coefficient of correlation 0.512±0.015.] 



Resistance in 1910. 


Rust resistance in 1911 (grades). 


Fre- 
quen- 
cy. 


Depar- 
ture 
from 
mean. 







1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


Grades: 

















1 
4 
12 
34 
47 
40 
32 
20 
9 


1 






2 

12 

36 

119 

138 

208 

175 

138 

84 

27 

6 


-5 


1 




3 
3 
1 


1 
1 
2 


1 

7 
3 
2 


'"'5' 
5 
5 

1 
3 


1 

6 
13 

7 
15 

5 


2 

1 

13 

12 

22 

13 

5 

1 






-4 


2 


1 


2 
34 
38 

74 
60 
52 
19 
4 
1 






-3 


3 


10 
23 

40 
39 
39 
29 
9 
3 


""'3' 

13 
22 
19 
26 
14 
2 


-2 


4 




-1 


5 






1 
1 





6 






-1-1 


7 






+ 2 


8 












+3 


9 














-f4 


10 


















+5 






















Frequency... 


1 


7 


6 


18 


19 


50 


69 


199 


285 


192 


99 


945 




Departure from 


-8 


-7 


-C 


-5 


-4 


-3 


-2 


-1 





+ 1 


+2 











It should be noted that very few plants show greater rust in 1911 
than in 1910. If the rust attacks had been of equal severity both 
seasons, a much higher value for the coefRcient of correlation would 
have been obtained. 

As was shown in Table XXI, there is a definite relation between 
increase in size and rust resistance. The young seedlings in the 
greenhouse lot show- a relation between rust resistance and size, 
but to a certain extent the size is dependent even yet on the size 
of tlie seed. In Table XXV the heights in September, 1911, are 
correlated with the rust resistance of plants as observed in Septem- 
ber, 1910. The first 25 lots of the greenhouse seedlings were used m 
this table, as the rust attack m 1911 on this row was more uniform 
than on the other rows, 

263 



52 



BREEDING ASPAEAGUS FOR EXIST EESISTANCE. 



Table XXV. — Correlation between height in 1911 (inches) and rust resistance in 1910, 
row 1 of greenhouse seedlings of 1910. 

[Height in 1911, subject; rust resistance in 1910, relative. Coefaeient of correlation 0.484±0.032.] 



Height in 1911. 




Rust resistance 


in 1910 (grades). 






Fre- 
quen- 
cy- 


Depar- 
ture 
from 

mean. 




1 


2 


3 


4 


5 


6 


7 


8 


9 


10 


Inches: 

12 










1 












1 

1 

3 

6 

4 

18 

29 

34 

38 

43 

32 

20 

17 

16 

6 

1 

3 

1 


_9 


15 










1 
1 










—8 


18 




1 




1 

1 


" "3 










—7 


21 


1 




1 






— 6 


24 


1 

3 

1 
2 
1 
3 


1 
2 
5 
2 
1 
1 
1 


2 
5 

7 
5 
11 
11 
6 
5 
2 
4 








—5 


27 




2 
5 
2 
3 
...... 



7 
9 
8 
7 
7 
1 
3 
2 










—4 


30 




2 
8 
S 
12 
13 
9 
3 
1 
4 


2 
3 
4 
8 
3 
3 
4 
2 
1 






—3 


33 




2 


2 


—2 


36 


2 


—1 


39 


1 

""2 
3 
3 
1 


...... 

...... 

3 
...... 





42 




-fl 


45 






+2 


48 . . 








1 


-1-3 


61 






1 


4-4 


54 






-1-5 


57 














-f6 


60 














1 


1 


1 
1 


+7 


63.. . 














4-8 






















Frequency 


s 


12 


14 


16 


54 


00 


01 


32 


14 


7 


273 








Departure from mean 


— 5 


— 4 


— 3 


— 2 


— 1 





+ 1 


+ 2 


+ 3 


+ 4 







SEEDLINGS OF 1911. 

In 1910 the work of making pedigree combinations was continued 
in the spring months. Tliis work was done before the rust developed 
and was naturally of a more or less hit-or-miss character. Male plants 
were selected for their individual qualities with the hope that they 
would transmit these qualities to their offspring. A7-19 and A7-83 
were used as check males to test new female plants. The female 
plants that had given the best resistance both in 1908 and in 1909 
were also used in making combinations with these males with the 
plan that if any of the 1909 combinations showed desirable resistance 
the 1910 lots of seed would furnish an additional supply of the desir- 
able progeny. 

The seed resulting from these pollinations was planted in 1911 at 
Concord, and when the rust attack developed in August the behavior 
of the different progenies was much the same as in 1910. A7-19 
proved to be a failure in point of transmission of rust resistance and 
has been discarded. A7-83, however, again performed in a very 
satisfactory manner. Its progeny proved highly resistant to rust 
and very vigorous in comparison with seedlings from American stock 
lacking in rust resistance. Plate XIII shows a row of seedlings from 
plants in row B24 (fig. 1) compared with the best resistant progeny 
"Martha Washington" (fig. 2). The strikhig difference in the two 
photographs is not so great as the contrast in the field, where the rich 
green of "Martha Washington" contrasts with the gray brown of the 
dead seedlings from row B24. 

263 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XIII, 




FiQ. 1.— Wakeman Seedling Stock, Showing Tops Entirely Killed by Rust. 
(Pliotiigraph taken September 25, 1911.) 




Fig. 2.-" Martha Washington" Stock (Progeny B32-39 X A7-83), Commercially 
Immune Plants of Strong Vigor. 
(Photograph taken September 2.i, 1911.) 

PEDIGREE SEEDLINGS OF 1911 AFTER A SEVERE ATTACK OF RUST. 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XIV. 




O 






I- u. 
2 CO 



Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture. 



Plate XV. 




Bui. 263, Bureau of Plant Industry, U. S. Dept. of Agricultur 



Plate XVI. 




UJ 


C) 


1 


;' 


1- 


< 




1- 


O 


(Tl 


H 


cn 


5 

n 


LLl 

a: 


I 




CO 


o 




< 


1- 


tr 


t/; 


LU 



Jul. 263, Bureau of Plant Industry, U. S. Dept. of Agriculture 



Plate XVII. 




:if Plant Industry, U. S. Dept. of Agriculture. 



Plate XVlll 





■%'^_M. i^Hrr ll 


, .1HP -^^5.^^ 


■hIk VL-viSdi 





Fig. 1.- 



-Seedlings at the South End of a Bed at Concord, Mass., in August, 
1910, Just Beginning to Rust. 




Fig. 2.— Seedlings at the North End of the Bed Shown in Figure 1 on the 
Same Day, Showing the Destruction of Plants Caused by Their Proximity 
TO A Young Bed on Which Cluster Cups Developed Abundantly. 



EFFECT OF RUST ON ASPARAGUS SEEDLINGS. 



BUD PROPAGATION^. 53 

Photograplis do not show the dead color of plants injured by rust, 
but in Plate XIV the effect of the 1911 rust attack is shown on 
American-grown Argenteuil stock, and Plate XV shows American- 
grown Reading Giant stock in an adjoining row. There is no ques- 
tion that Reading Giant contams plants of greater resistance than 
any to be found in any lot of Argenteuil grown on the station grounds 
at Concord. Plates XIV and XV show tliis difference about as it 
occurs in the regular field growth of the two stocks. The seedlings 
from A7 -83 progenies are superior to these standard strains in both rust 
resistance and vigor (PI. XVI) . B32-39 gives very resistant seedlings 
even when open fertilized -with males of medium resistance (PI. XVII). 
The small size of the seeds of this plant places the seedlings at a dis- 
advantage, and the combination with A7-83 is needed to give vigor. 

In the tests of 1911 no new progeny lots showed a resistance or vigor 
comparable with that of "Martha Washington." Most of the plants 
tested will be discarded, a few females being held for a further test. 
New selections from Reading Giant and from A7-83 progeny are 
included in the pollination work in 1912. Some of these new selec- 
tions show such a high individual resistance that it is practically cer- 
tain that some of the new combinations with A7-83 will show great 

resistance. 

BUD PROPAGATION. 

In order to increase the product of seed from individual plants it 
will be necessary to carry out some methods of vegetative propaga- 
tion. Prelimmary experiments to this end were undertaken in the 
greenhouse in 1910. Seedlings planted January, 1910, were separated 
when they had several shoots; the roots were divided more or less 
evenly and the plants repotted. Nearly all of them grew, and in 
about a month they were separated again. This was kept up until 
in January, 1911, two seedling plants were represented by 60 or more 
plants. When properly handled few plants die. In the fall of 1910 
about half the crowns of No. 1 Washington, No. 2 Martha, B32-4, and 
A2-23 were dug up, shipped to Washington, and planted in the green- 
house. These crowns were split into several smaller clusters and 
planted in 12-inch pots. New shoots started, but on account of low 
temperature did not completely develop, and finally died back. 
When the pots were moved into a warmer house the divided crowns 
started growing again, and some of the plants have been divided a 
second time. This method of vegetative propagation will be neces- 
sary in breeding and seed-growing work. 

PEDIGREE. 

In pedigree breeding work the performance of the parent indi- 
viduals is not important in itself, and is only of value as it shows the 
ability of the plant to transmit its good qualities to its offspring. 

263 



54 BEEEDIFG ASPAKAGUS FOE BUST KESISTANCE. 

These plants selected for breeding purposes become valuable only as 
their progeny show uniformly high quality and yield. So when a 
pedigreed progeny shows a high commercial value its parent plants 
become of great importance. They should be increased as fast as 
possible by clonal propagation and should be isolated and allowed 
to produce as much seed as possible. It is now that records and 
history become important. Careful record should be kept of their 
original source, etc., and future development. 

In carrying out the work on this breeding project and of private 
breeding work developing from it the following scheme will be used: 

Number. — Each plant that proves of value as a breeding parent 
will be assigned a permanent serial number. These numbers will not 
be given to a plant until its progeny show it to be of value as a breed- 
ing parent. Its preliminary records will be kept under a temporary 
number used to mark its location in the testing plat. 

Name. — Plants used to produce progenies for commercial planting 
will be given names as follows: The male plants will be given sur- 
names as Washington, Wilson, Prescott, 'V\^ieeler, Moore, etc., the 
name assigned to one plant not to be duplicated in the future. 
Female plants will be named by assigning them different feminine 
names, as Martha, Mary, Edith, etc. 

Progenies wiU take their commercial or trade names from the two 
parents. Thus the progeny of No. 2 Martha X No. 1 Washington 
will be known to the trade and growers as "Martha Washington"; 
No. 3 Edith X No. 1 Washington would be "Edith Washington"; 
No. 2 Martha X No. 4 Wheeler would be "Martha Wlieeler." In 
this way each progeny would by its name indicate its parents. 

Records. — In keeping pedigree records the loose-leaf record book 
will be used. A primary sheet for each parent admitted to registry 
will be used, giving its history, description, etc. The performance of 
the plants as shown by their progeny records wiU be filed under the 
female parent as secondary sheets. An abbreviated record of these 
progeny sheets will be filed under the male parents as secondary 
sheets to show the performance. 

No. 1. Washington $ . 

Pedigree: J^^^^^^^^^^- 
$ unknown. 

History: Original plant found in 1908, location A7-83. New American Concord- 
grown stock by Anson Wheeler. Marked as best male in type and rust 
resistance. Used in 1909 and 1910 in crossing work. In 1911 used as test 
male in all crossing work. 

Progeny: Very resistant to rust and showing an added vigor above open- 
fertilized progeny no matter what female parent was used. 

Propagation: Part of original parent dug up in 1910 for clonal propagation. 

263 



PLANS FOR DISTEIBUTION. 55 

No. 2. Martha 9 . 

Pedigree: 9 unknown. 
$ unknown. 

History: Original plant found in 1908, location B32-39. Reading Giant stock. 
Marked as best in rust resistance 1909; rather small type; used in 1909 and 
1910 in crossing work. In 1911, under cage, crossed with No. 1. 

Progeny: Open-fertilized lots of 1909 and 1910 better in resistance than any- 
other open-fertilized lota tested. X No. 1 progeny best for resistance and 
type of any seedlings grown. 

Propagation: Part of original parent dug up in 1910 for clonal propagation. 

When plants from any named progeny develop as good breeding 
parents they will be assigned new names and handled as distinct 
parents, their history and pedigree being recorded on their original 
pedigree sheets. 

When by vegetative propagation the original parent plants have 
increased so that different growers have lots of the same progeny, in 
offering them for sale the grower's name should accompany the 
progeny name for purposes of identification in case any error creeps 
in; as, Martha Washington (Frank Wheeler stock), Martha Washing- 
ton (C. W. Prescott stock) . The registry of new parents for breeding 
purposes should be through a central breeding organization, so that 
no duplication of names will occur. For the present this work can 
be done at the experimental station at Concord. These new i)rogeny 
lots must be tested in competition with some standard progeny of 
known rust resistance and quality and their general value determined. 

PLANS FOR DISTRIBTJTION. 

When sufficient stock of any progeny is obtained to warrant dis- 
tribution to interested growers, plans will be made to plant the stock 
under conditions favorable to the satisfactory testing of these prog- 
enies for resistance to rust. The lots of seed or seedlings issued by 
the Department will, as far as possible, be sent to growers who will 
be in a position to aid in extending the cultivation of the rust-resistant 
strains. 

SUGGESTIONS TO BREEDERS AND GROWERS. 

In giving advice in regard to asparagus breeding at this time it 
must be remembered that our experiments are only just begun. 
Later results are liable to change the methods of procedure to be 
recommended, but the methods and practices at present followed are 
here outlined. 

RUST RESISTANCE. 

If rust is a factor in the region where the work is to be done, resist- 
ant varieties are of prime importance. In order to secure resistant 
selections rust must be present in abundance. Unless one can pick 

263 



56 BKEEDING ASPAKAGUS FOE BUST KESISTAN"CE. 

the one superior plant out of a thousand in point of rust resistance 
the work will be hard. 

Late fall is the best time for making field selections, because at 
that season the rust will be developed sufficiently to have marked 
the nonresistant plants m the field so that they can be disregarded. 

In providing rust for this work in New England it will usually be 
sufficient to leave an area of nonresistant plants in one corner of the 
field, preferably that from which the prevailing winds come. If 
there was plenty of black rust the preceding season, the spring stage 
wiU develop in sufficient abundance to provide rust for infection 
work later in the season. A bed of young asparagus not ready to 
cut for market is usuaUy sufficient to provide a lodging place for the 
spring rust. Artificial inoculation has not been necessary at any 
time in our breeding fields. 

ISOLATION. 

After two mated plants have had their progeny tested and have 
proved their value as a breeding pair they wiU be dug up and propa- 
gated by crown division to secure a stock for breedmg. This stock 
will be isolated and used only to grow seed. 

Isolation wiU be secured by building an insect-proof cage over the 
field or by planting remote from other fields or wild plants, so that 
bees will not be able to carry in foreign poUen. The mesh of any 
cage wifi have to be small enough to keep out the small wild bees. 
One of the probable methods will be to grow the plants in the green- 
houses in the winter. During the winter of 1910-11 in Washington 
we have been very successful in setting seed in the greenhouse by 
hand poUination. In making seed plantations a grower wiU not be 
limited to one female plant— any number may be planted with one 
male. Whenever it is desired to use two males a separate field must 
be used for each. 

PROGENY BED. 

In planting seed for a progeny test a uniform piece of good land 
is necessary. The presence of shade, such as overhanging trees, 
near-by buildings, etc., should be avoided. The bed should be set 
so as to be uniformly exposed to the attacks of rust from near-by 
infection plats. Any marked difference in moisture supply is apt to 
interfere with the test. 

As it is not the intention in the progeny test to grow large plants, 
the custom at the Concord station has been to plant rather late m 
May so that all danger of frost and also of the first crop of beetles is 
past. About 10 feet of seedlmg row is sufficient for a fair test. Of 
course, many lots of seed will not plant so much as that, but it is a 

263 



SUGGESTIONS TO BKEEDEES AND GROWERS. 57 

useless waste of space to take any more. Rows are first laid out 
with a line and then made about 2 mches deep with a hoe. The 
seed is sown by hand and covered with a rake. Sldll in planting is 
acquired by experience, the intention being to drop about six seeds 
to the foot. A space of 18 inches between rows is ample to allow for 
passage and cultivation. The two things to judge in the first year 
are height and rust. The rust on the seedlings is closely correlated 
with the rust of the plant in future years and height is correlated 
with size and vigor. The first year progeny test will eventually be 
the main test of any plant's value in breeding work. 

The use of a standard or uniform lot of seedlmgs as a check on 
rust infection is desirable, and where accurate results are expected 
is necessary. In our work up to 1912 we have used Reading Giant. 
Pedigree stock of good quality alternating with rusty stock will be 
planted hereafter as a double check. 

VALUE OF BREEDING METHODS. 

If asparagus growers ever hope to secure reasonably uniform 
strains of fixed type, the methods of commercial seed production 
will have to be changed from their present unscientific condition. 
With few exceptions no attention is now paid to the male parent and 
little effort is made to get good female plants, the process of seed 
selection consisting largely of going into a field that has made a good 
growth and harvesting seed stalks that have well-grown seed. 

Ml". Frank Wheeler, of Concord, Mass., has for several years made a 
practice of selecting the best male and female plants in regard to 
type, vigor, yield, and rust resistance. These plants have been 
allowed to grow and bloom during the cutting season. The seed is 
saved from only those stems of the female plants that bloomed 
before the general field plants came into flower. These seed plants 
are the progeny of imported Argenteuil stock and produce a very 
desirable quality of seedlmgs. 

In the spring of 1908 about 400 one-year plants of tliis strain were 
planted in comparison with a similar plat of a strain known locally 
as "Small" Argenteuil. The yields from these two plats were kept 
in 1910 and 1911, as shown in Table IV on page 26. 

This difference in yield is apparently due to the difference in the 
strains in which the selection for large stalks by Mr. Wheeler has 
been an important factor. No apparent difference was noticed in 
the comparative rust resistance of the two lots, so that rust does not 
enter as a factor. 

If the above striking difference exists through the simple selection 
methods used by Mr. Wheeler, would not other good farmers be 

263 



58 BREEDING ASPAEAGUS FOR EXIST EESISTANCE. 

justified in trying pedigree methods in growing seed? The above- 
mentioned stram is not pedigreed from either side, the parentage 
complex mcluding about 20 uidividuals of each sex. Mr. Wheeler 
in 1910 and 1911 planted his lots of seed from each female in separate 
rows. The difference was so strikmg that in the future pedigree 
methods will receive more attention. 

PROTECTION FROM BEETLES.^ 

One thing to be considered m seed production is the effect of the 
red or twelve-spotted asparagus beetle (Crioceris 1 2-punctatus) , the 
larval stages of which live in and destroy the asparagus berries. 
This beetle proved a serious factor in the breeding work last year, 
and is liable to become worse as time goes on. The first specimens 
of this beetle found in Concord were discovered in the fall of 1908. 
The fall of 1910 showed nearly as many as of the ordinaiy species, 
Crioceris asparagi. Paper bags are not sufficient protection, as in 
several cases the berries under bags were destroyed. The beetles 
had either laid then- eggs before the plants were bagged or else 
crawled up inside through the open spaces around the stems. Cages 
of 16-mesh wire fly screen keep out the red beetle but let in the 
smaller specimens of the common asparagus beetle. Both kinds 
may be kept out by the use of 18-mesh wire screen, which will be 
hereafter used. 

PROTECTION OF NONIMMUNE FIELDS. 

Spraying methods have been developed by different experiment- 
station workers in the past that if carefully followed by the grower will 
keep down the rust. The trouble in applying sprays and the high cost 
of their efficient application has kept many good growers from using 
them. Some farmers have gone out of the asparagus business while 
others have secured the best stock they could find and by careful 
methods have kept on. The high prices caused by increasing demand 
and lessening supply has made the profit in asparagus really higher 
than it was before the rust became known in the country. 

It is now certain that by proper pedigree breeding work the whole 
question of noticeable rust injury in asparagus may be eliminated. 
At the same time the pedigree breeding work will make uniform and 
vigorous strains, thus greatly increasing the yield per acre. The 
elimination of rust as a factor in asparagus growing will render larger 
yields possible, so that the market price in many locations where rust 
now prevents adequate returns will fall within reach of the large body 
of consumers. At present in most regions asparagus is a luxury. 

1 For a full discussion of the two asparagus beetles and of the methods to be used for their control, the 
reader is referred to Circular 102 of the Bureau of Entomology, U. S. Department of Agriculture. 
263 



SUGGESTIONS TO BKEEDERS AND GROWEES. 69 

SUGGESTIONS FOR RUST PREVENTION. 

Although the breeding work being carried on with asparagus will 
eventually lead to the control of rust in commercial plantings, several 
years must elapse before this result will become effective. Meanwhile, 
it is necessary to take all measures practicable to prevent the destruc- 
tion of existing fields of asparagus by the rust. To this end the main 
factor is to keep the rust away from the fields in summer just as long 
as possible. 

As pointed out by Smith and others, wild asparagus growing around 
the borders of the fields, along fences, ditches, etc., is one of the worst 
enemies of the grower. These wild plants act as infection centers and 
tlieir influence can be easily traced later in the season when the cutting 
beds have grown up. During the summer of 1910 the writer made an 
examination of the fields near Concord just at the time the rust was 
coming on and in every case of infection was able to trace the cause to 
asparagus plants that had not been cut up to the close of the infection 
period of the spring rust (PI. XVIII). When rust was found in a 
commercial field by following it up to the northwest, the direction 
from which the prevailing winds come, a young bed, an old neglected 
bed, or wild asparagus was found in every case and always with the re- 
mains of cluster-cup infections. Wild plants wherever found should 
be dug up and burned. New beds should be planted only at rare 
intervals of time and then if possible where they will be to windward 
of a cutting bed. Keep the seedlings out of the cutting bed, at least 
let none stay in at the time the bed is allowed to grow up after the cut- 
ting season. Allow no poor shoots to grow up in the cutting field. 
In other words, keep down every shoot of asparagus until the middle 
of June in the latitude of Boston and see that neighboring farmers do 
the same. In the fall the tops should be removed carefully from 
1-year-old beds that are not to be cut the next year. This will in a 
large measure reduce the liability of infection from this source. 

The writer does not recommend the removal of tops from a mature 
bed in the fall. The ordinary practice in the vicinity of Concord is to 
leave the bed undisturbed in the fall so that the tops will act as a 
winter cover and prevent the blowing of soil or snow. In the spring 
these tops are cut with a disk harrow. Fields in which this treatment 
had been used have been examined for spring rust after the bed had 
grown up at the end of the cutting season, but in no case have cluster 
cups been found. The Massachusetts station has at Concord a 3-acre 
fertihzer experimental plat on which plants have been infected during 
1909, 1910, and 1911 from young beds near by that were not being 
cut. No cluster cups were found in this 3-acre bed except on plants 
left for breeding purposes. 

263 



60 BEEEDING ASPAEAGUS FOR RUST RESISTANCE. '^i' 

SUMMARY. 

Puccinia asparagi, the European asparagus rust, was discovered in 
America m 1896 and in the next six years spread over the asparao-us- 
growing regions of the United States, causing great damage. In^the 
. Eastern States no successful remedy was found, although some strains 
were found to be more resistant than others. Among the resistant 
varieties were Argenteuil and Palmetto. 

The Massachusetts Asparagus Growers' Association, organized in 
1906 to obtain a resistant variety by breeding, secured the coopera- 
tion of the Massachusetts Agricultural Experiment Station and the 
Umted States Department of Agriculture in establishing experimental 
grounds for this work at Concord. 

Previous work on the life history of the disease shows that the rust 
m aU Its stages occurs only on asparagus and that the uredo stao-e is 
the most injurious. The injury is due to the mechanical and physio- 
logical effect on the summer growth which prevents the storage of 
food supplies for the growth during the next cutting season. 

A large number of strams from America and Europe have been col- 
lected and tested for rust resistance. No varietv proving uniform or sat- 
isfactory, breedmg work was undertaken to produce a stock that would 
be commercially immune. Some wild species have been imported from 
the Old World and one or more hybrids have been produced. 

In makmg selections for rust resistance several acres of the best 
stock obtainable were used. From the different strains several 
hundred plants have been selected for pedigree testing after being 
subjected to attacks of rust. 

Rust resistance in asparagus seems to be based upon structural 
differences. Vigor is not necessarUy correlated with resistance. 

Breeding work in asparagus is complicated by the fact that the 
species IS dioecious, so that two parents must always be used in seed 
production. Hand pollination is used for pedigree work. 

Progeny tests of select plants have been made each season since 1909. 
The rust resistance and vigor of these seedlings have determined the 
value of the breeding parents. The test male A7-83 and the test fe- 
male B32-39 have given a very superior progeny, which has proved 
satisfactory as a ''commercially immune" type. This progency has 
been named and plans are under way for its production in quantity. 

In carrying out the breeding work, studies have been made of the 
effect of the weight of seed on seedling vigor, the effect of seedling size 
on the plant in the field, etc. Correlations between size of plant, yield, 
rust resistance, etc., have been of value in carrying out the work. 

Bud propagation of select breeding parents has been inaugurated 
to promote more extensive seed production. 

Breeders and growers are advised to take up pedigree breeding to 
produce good strains and to use careful methods in keeping rust out 
of producing fields. 

263 

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